Состав акриловых красок: состав и свойства, виды и технические характеристики

Акриловые краски для стен и потолков: характеристики и свойства

Акриловая краска – разновидность воднодисперсионных лакокрасочных материалов. А это значит, что она имеет практически такие же преимущества. Может использоваться для окрашивания ткани, кожи, фарфора, дерева и других поверхностей. Состав включает в себя три основных компонента: акриловая полимерная эмульсия, красящее вещество, вода. Это и сделало акриловые краски такими популярными. Есть еще и другие факты, которые помогут узнать особенности материала и принцип работы с ним.

Свойства акриловой краски

А криловая краска для стен сделана на основе воды. После нанесения состава на поверхность, вода начинает высыхать, а на стене образуется прочная пленка. Она влагоустойчивая и паропроницаемая, это значит, что стены будут дышать, микроклимат внутри не ухудшится.

Характеристики и свойства краски:

1. Устойчивость к загрязнениям. Если поверхность испачкается, поверхность можно очистить влажной тряпкой.
2. Универсальность. Используется для обработки железобетона, металла, штукатурки, пластика, дерева и других поверхностей.
3. Устойчивость к влаге. Первозданный вид покрытия не будет испорчен, стену можно протирать влажной тряпкой. Это не повлияет на качество поверхности.
4. Быстрое высыхание. Вода очень быстро испаряется после нанесения. Это зависит от температуры внутри и других факторов. Примерно через 2 часа можно приступать к нанесению второго слоя.
5. Отличная укрывистость. Акриловая краска, качественная, для стен и потолков может скрыть с мелкие дефекты покрытия, замаскировать трещинки и ямки, глубиной до 0,6 мм. Достаточно нанести всего 2 слоя лакокрасочного материала, чтобы устранить их.
6. Устойчивость к ультафилетовым лучам. Она защитит стены и потолок, а сама не будет выцветать длительный период.
7. Не боится перепадов температур поэтому ее используют на кухне и в подобных помещения.
8. Экологически чистая. В составе отсутствует разбавитель для акриловых красок, и если не использовать подобные растворители, то лакокрасочный материал пригоден для детской.
9. Не имеет запаха, является гипоаллергенной.
10. Экономичность. Расход довольно маленький и составляет от 100 до 110 г/кв.м.
11. Оптимальная стоимость за такое качество товара.
12. Богатая палитра цветов. Поверхность приобретает сочные и яркие цвета.

Важно! Выбирая составы на акриловой основе, важно учесть, что при высыхании цвет становится немного темнее.

Данные лакокрасочные материалы ценят за их прекрасные эксплуатационные характеристики. С ними легко работать, состав эластичный, упругий и прочный.

Выбор акриловой краски

Одной из лучших считают именно водоэмульсионный акриловый лакокрасочный материал, сделанный на базе акриловых смол. Другие доступные варианты: винилкариловый, акрилсиликоновый и стироакриловый. Все они сделаны на базе акриловых сополимеров.

С учетом дополнительных компонентов, акриловая краска бывает для внутренних отделочных работ, для сухих и влажных помещений. Если нужно покрасить сухое помещение, то покупается краска для сухих помещений, а не наоборот. Использовать можно только по назначению.

Изначально лакокрасочный материал продается белого цвета. Чтобы сделать его цветным, используются пигмент и красители, которые добавляют в банку с краской. Чем больше пигмента, тем насыщенней и ярче цвет. В магазинах есть уже готовые составы с добавленным цветом.

Лакокрасочный материал бывает глянцевым и матовым. Первый вариант позволит визуально расширить комнату, придать ей блеска. А матовые поверхности скрывают некоторые дефекты стен. Выбирать состав рекомендуется из таких фирм:

• Тиккурила;
• Сиро мат плюс;
• Dulux;
• Dufa;
• Иннетак.

Как подготовить поверхность

Для начала подготовляется помещение. Мебель удаляется или укрывается пленкой/бумагой. Сам мастер облачается в одежду, которую не жалко испачкать, надевает перчатки и головной убор.

Стены и потолок очищаются от старого отделочного материала. Пользуйтесь шпателем или губкой, в зависимости от отделки. Для удобства она смачивается теплой водой. Особое внимание уделяется углам и местам стыка стены и потолка.

Все трещинки, щели, углубления нужно удалить. Поверхность перед окрашиванием должна быть идеально ровная, чистая и сухая. Устранит дефекты шпаклевка. Заключительный этап – грунтование стен и потолка. Оно улучшит адгезию и уменьшит расход.

Если предполагается покрасить акриловой краской деревянную поверхность, предварительно она должна быть обязательно загрунтована. Тогда дерево не будет впитывать в поры состав, увеличивая расход.

Подготовка краски и инструмента

Изначально акриловая краска густая. Это как хорошо, так и не очень, ведь густота не позволит скрыть стыковочные полосы при окрашивании. Она разбавляется водой, чтобы окрашиваемые поверхности смотрелись идеально. Производитель указывает, оптимальную консистенцию. Обычно в банку требуется добавить 5–10% воды.

Есть краски, которые не нужно разводить. В инструкции указано просто «перемешать». Это в большинстве случаев касается окрашивания в 1 слой.

Для покраски стен и потолка потребуются кисть или валик. Кисть используется для труднодоступных мест (углы, участки за радиатором), а валиком удобно и быстро работать на разных поверхностях. Вместе с валиком рекомендуется приобрести ванночку, чтобы контролировать количество краски. Для удаления погрешностей требуется тряпка.

 

Окрашивание кистью

Наносят краску аккуратно, чтобы не образовывались подтеки. Набирать на кисть много акрилового состава не нужно. Для контроля на банку натягивается резинка, благодаря которой удаляется лишняя краска. Вытирать кисточку о саму банку нельзя.

При нанесении инструмент держится перпендикулярно к стене или под небольшим углом. Движения плавные, равномерные. Полосы формируются широкие, затем они растушевываются. Ручка держится как можно ближе к поверхности, а при движении угол наклона увеличивается. Для отделки потолка используется соответствующий состав. Красить стены потолочной краской не рекомендуется.

Чтобы получить гладкую поверхность, наносимые штрихи нужно перекрещивать: один мазок вверх, другой вниз. Время от времени кисть проворачивается на 180°. Щетина будет изнашиваться равномерно.

За счет быстрого высыхания акриловой краски, при перерыве нельзя допускать осушение кисти. Она задубеет. После окончания работ инструмент промывается растворителем.

Окрашивание валиком

Работать с помощью валика проще и быстрее. Акриловая краска наливается в лоток, в него опускается валик и путем прокатывания по лотку, инструмент пропитывается ею. Это позволит и удалить лишнюю разведенную жидкость и покрасить потолок без разводов.

Дальнейший процесс прост: окрашивание начинается не с угла, а с 1 м от него. Лакокрасочный материал распределяется по поверхности, валик при этом проводится от себя. Мазки делаются перекрестно друг относительно друга. Это позволит не оставить следов и равномерно распределить состав по поверхности.

Технология окрашивания

Рассмотрим подробней, как выполняется покраска стен акриловой краской. Если, работая с кистью, сильно нажимать на нее, то будут образовываться подтеки, слой формируется тонким, полоса широкая. Делая слабый нажим, полосы получаются узкими и с пропусками. В идеале, сначала делать нажим слабым, а когда краски на кисточке становится меньше, усиливать.

Рекомендуем перед тем как пользоваться акриловыми красками, испробовать себя на ненужной поверхности, набить руку. Этапы окрашивания такие:

1.     Наносится первый слой параллельно лучам солнца. Начинают от углов и труднодоступных мест.

2.     После высыхания наносится второй слой, он перпендикулярный первому. Технология такая же.

3.     Третий слой перпендикулярный второму. Так как в составе смесей есть вода, то слой будет быстро высыхать. Главное, хорошо распределять вещество, чтобы не образовались подтеки.

После каждого слоя проверяется качество окраски, в зависимости от правильности нанесения. Никаких пропусков и полос. Если такие есть, они исправляются до высыхания красящего вещества.

Акриловая краска – один из лучших материалов в своей сфере. С ней легко работать новичку. Она долговечная, имеет защиту от влаги и не выгорает со временем. К тому же запах отсутствует, после окрашивания можно сразу заселяться. Так как состав отличаются экологичностью. Его можно использовать в любых комнатах.

90000 The Pros & Cons of Artist Grade Acrylic Paints 90001 90002 By Rose Welty in Art Tutorials> Painting Tutorials 90003 90002 90005 The following article focuses on the history and current state of acrylic paints-it is the first in a new series. Future articles will cover acrylic painting techniques and methods. 90006 90003 90008 90009 90010 90008 A brief overview of artists ‘acrylic paints 90010 90002 Acrylic paint was first developed in the 1950s as house paint, and made commercially available as artist grade paints in the 1960s.The term 90005 -acrylic- 90006 refers to the fact that the pigment for the paint is suspended in an acrylic polymer emulsion. 90003 90017 Quick announcement — 90018 EmptyEasel has created a 90017 quicker, easier way for artists to have their own art website. 90018 Click here to learn more and get a simple art website of your own! 90002 When you compare acrylic to oil paint, where pigment is suspended in oil (usually linseed oil) and the name makes perfect sense. Water is used to combine the pigment and emulsion in acrylic paints, therefore acrylics are considered to be «water-based.»90003 90002 Depending on the painting techniques used, acrylic paintings may look similar either to oil paintings OR watercolor paintings. Of course, acrylic paint can also be applied in such a way that it is 90005 clearly 90006 an acrylic painting, and not oil or watercolor. 90003 90002 Currently there are two types of acrylic paints on the market. I’ll refer to them as «traditional» acrylic paints and «new» acrylic paints. 90003 90002 Traditional acrylic paints are the fast-drying paints that have been around for the last 50 years.They are made by Liquitex, Winsor and Newton, Golden, Grumbacher, and others. Newer acrylic paints do not dry as quickly and can be reactivated after drying. They are made by Golden and Chroma. 90003 90002 Here’s a quick explanation of the advantages and disadvantages of acrylic paints, whether you’re using traditional acrylics or «new» acrylics: 90003 90033 Advantages and disadvantages of traditional acrylics: 90034 90002 90017 Toxicity Levels 90018 90003 90002 Advantages — Acrylic paints are water-based, which means they can be thinned with just water (no toxic spirits are required).In addition, wet paint can be cleaned off of brushes with soap and water. 90003 90002 Disadvantages — Acrylic paints can contain toxins within their pigments, just like some oil paints do. Using «retarder» to slow the drying time of acrylics often introduces additional toxins. 90003 90002 90017 Drying Time 90018 90003 90002 Advantages — Traditional acrylic paints dry rapidly, so there is no need to wait between painting sessions for layers to dry. Paintings are dry enough to ship safely within a day or so.90003 90002 Disadvantages — Because acrylic paints dry quickly they can not be easily blended to create the «wet in wet» technique that is popular with oil paints. This is what can give a «harsher» look to acrylic paintings when compared to oils. 90003 90002 Acrylic paint also dries quickly on the palette. There are special palettes designed to extend the life of acrylic paint outside of the tube, but for slower painters, this can be a big problem. 90003 90002 90017 Reactivation 90018 90003 90002 Advantages — Unlike watercolors, another water-based paint, once traditional acrylics are dry they are on the support to stay.This makes painting new layers on top of previous ones simpler. 90003 90002 Disadvantages — Once the paint is dry, it can not be removed or altered. 90003 90002 90017 Durability 90018 90003 90002 Advantages — Acrylic paints have been proven to be more flexible than oil paints. There is no need to follow «fat over lean» rules with acrylics so that they will not crack. 90003 90002 Disadvantages — We’ve only had 50 years of acrylic paints. . . how they’ll hold up after a few hundred years can not be proven for another 150 years.Certainly, acrylics appear to be more durable now than oil paints, but one must remember that they have not yet passed the acid test of time. 90003 90033 Advantages and disadvantages of new acrylics: 90034 90002 90017 Toxicity Levels 90018 90003 90002 There are no differences between traditional acrylics and newer acrylic paints, except that you will not need to use any toxic retarders to slow drying time (see below). 90003 90002 90017 Drying Time 90018 90003 90002 Advantages — New acrylic paints have extended drying times, so the paint can be left on a sealed palette and remain workable for several days.Also, wet-in-wet techniques can be used, just like oil paints, without a retarder. 90003 90002 Disadvantages — If you like your acrylics to dry very quickly, these will not. 90003 90002 90017 Reactivation 90018 90003 90002 Advantages: These paints do reactivate. When water is applied to paint that is dry to the touch, it can be reactivated, worked into and / or lifted off. Over time, this ability to reactivate is eventually lost. 90003 90002 Disadvantages — Painting wet over dry acrylics may cause some color bleed.90003 90002 90017 Durability 90018 90003 90002 Advantages — Same as traditional oil paints. 90003 90002 Disadvantages — These paints are even «younger» than traditional acrylic paints. Efforts are being made to prove their longevity, but nothing can be irrefutably proven until sufficient time passes. 90003 90002 That’s all for today’s article. . . I hope it’s given you some idea of ​​where acrylic paints come from and how they work. 90003 90002 Next time we’ll go a bit deeper and cover acrylic painting techniques.Stay tuned! 90003 90002 90033 90017 GET EMPTYEASEL IN YOUR INBOX 90018 90034 90003 90002 We’ll send you articles & tutorials right as we publish them, so you never miss a post! Unsubscribe here at any time. 90003 90002 90005 NOTE: You may also be interested in EE’s step-by-step drawing guide for artists. Click below to learn more! 90006 90003 90117 90002 This post may contain affiliate links. 90003.90000 Aspects of Longevity of Oil and Acrylic Artist Paints 90001 90002 90003 90002 90005 90006 Professor Frank N. Jones 90007 Coatings Research Institute 90007 Eastern Michigan University 90009 90010 90003 90002 This article will compare acrylic and oil artist paints from the point of view of a scientist who specializes in coatings. It is not meant to be the «end-all» source on the topic. However, it is meant to make the reader more informed regarding long-term durability issues for both these materials.90003 90002 Below are three excerpts from recent artists ‘list serves and internet chat rooms regarding the quality of oils and acrylics and the information available to them. These statements will help guide us as we explore the archival qualities of oil and acrylic artist paints. 90003 90002 90005 — «Acrylic paint is the MOST stable and permanent material available to the artist today and if properly used will outlast all other materials.» [1] 90010 90003 90002 90005 — «One should beware of acrylic paints … At first … they were thought to be wonder media, but the binder has aged faster than oil colors and has caused the colors to yellow.»[2] 90010 90003 90002 90005 — «Man o man … so much information and it’s all good.» [3] 90010 90003 90002 The first two people making the statements above feel strongly in their differing opinions, so where does that leave the artist? Probably uncertain about long-term durability of the materials they use. This article will help the artist become more aware of the issues associated with each material by focusing on such areas as film formation, film degradation, cracking, yellowing, cleanability, adhesion, and fading.This will give them the knowledge necessary to make an informed decision about the medium they use and what their artwork might look like in 500 years. In order to do this, we must first understand how paint films form. 90003 90002 90006 1. Film Formation 90007 90009 90007 To visualize the polymer molecules that hold paint films together, imagine a large mass of cooked spaghetti, with very long, strong strands. The strands are roughly analogous to polymer chains. The mass of material can be deformed because individual strands can bend and slide past one another, but movement is partly restricted by tangles.Touching this mass, one would sense that it is solid but not rigid; it is rubbery. Now imagine that we begin randomly gluing strands together at small points where they intersect. These connections furnish additional resistance to deformation. As we glue more and more strands together, the mass becomes more and more rigid. Finally, when the strands are all glued together at many points, the mass becomes very rigid and can be deformed only by breaking strands. The mass resists deformation, but under sufficient stress, will crack.The gluing together of individual strands is analogous (again roughly) to what polymer chemists call «cross-linking.» 90003 90002 On the canvas, acrylics and oils end up as high molecular weight polymer (see Glossary) films, essentially thin layers of plastic, usually containing a lot of pigment particles. But there are big 90007 differences as to how they get there. 90003 90039 90040 Oil paints in the tube are primarily vegetable oils, such as linseed oil, and pigment. Oils harden after they are applied to the canvas in a complex chemical process in which they react with oxygen.This process forms longer chains and many cross-links, leading to a cross-linked network of polymer. Because the oil molecules were relatively small at the start, many cross-links are required to reach a satisfactory state of hardness. The chemical reactions get slower as the film hardens, but they never completely stop (under normal display and storage conditions). Over time, continuing cross-linking can cause the film to become too brittle. 90041 90040 Acrylics are polymerized before the paint is manufactured, and no further chemical reactions are needed to form a film.The acrylic polymers are very large molecules (long strands) that form films through a process called coalescence (see Glossary) and do not need to be cross-linked to form a good film, although sometimes they are polymerized in a way that induces a small level of cross-linking. Recently painted acrylic films are softer, more flexible and less brittle than oil paint films (except perhaps at cold temperatures — see below). Acrylic films can undergo chemical changes as they age, but when a painting is kept indoors these changes that cause hardening, are very slow.90041 90044 90002 Now that we have a better understanding of how films form, we need to explore the causes of film degradation. 90003 90002 90006 2. What can cause paint films to physically degrade? 90009 90003 90002 Polymer films can undergo degradation in several ways. Two common ways can be classified as (1) chemical changes that increase cross-linking beyond the optimum level and (2) chemical changes that gradually break the polymer chains. Excessive cross-linking makes paint films brittle and vulnerable to cracking and flaking.Breakage of polymer chains results in smaller molecules, and if a large number of chains is broken, the films weaken and in extreme cases, disintegrate. 90003 90002 As noted above, oils would not harden without cross-linking, which for artist oils, usually takes months to reach an optimum level. By then, the chemical changes that cause cross-linking will have slowed, but they do not stop. The ongoing chemical changes cause oils to become harder, less flexible, and more brittle as they age. 90003 90002 There are also chemical reactions that can break the polymer chains in oils.The most common is chemical reaction with water. This reaction is usually slow, but it gets much faster if the paint film is exposed to humid air under alkaline conditions. This becomes a problem if the paint is formulated with alkaline pigments or if it is applied over an alkaline surface. Alkaline pigments may cause general deterioration, and alkaline surfaces may cause loss of adhesion. Masonry (brick, concrete, plaster, grout, stucco) surfaces are often alkaline, and it is undesirable to paint them with oils.90003 90002 On the other hand, acrylics do not need to cross-link to form good films. The acrylic polymers used in modern acrylic paints are designed with the goal of making them resistant to chemical changes resulting from reactions with oxygen and water and by exposure to ultraviolet light. This goal is not completely achieved, and chemical changes occur slowly as paintings age. The changes are slow outdoors and much slower especially under indoor conditions. While it is not known how long acrylic films will retain their physical qualities, evidence presented below suggests they will last hundreds if not thousands of years.The chemical changes that could occur might either cause chain breakage or additional cross-linking. Lastly, the combination of humid air and alkaline conditions has little effect on acrylics, making them a paint of choice for alkaline surfaces such as masonry and plaster. 90003 90002 Pigments can influence degradation rates in several ways. First, the pigment particles themselves may deteriorate, usually causing a change in color. Fading is discussed below in Section 7. Second, pigments may affect the polymeric binder.For example, certain grades of titanium dioxide white pigments can catalyze photochemical deterioration; in the most appropriate grades of titanium dioxide, each particle is coated with glass and / or alumina to prevent this. As another example, high loadings of many types if pigments can make the paint harder and less flexible; this is generally a manageable problem, but high loadings in paints that tend to embrittle with age could potentially accelerate problems such as cracking. On the other hand, certain pigments such as iron oxides and carbon blacks are good UV screeners and generally enhance the outdoor weatherability of paints.90003 90002 90006 3. Cracking 90009 90003 90065 90002 Above is an example of an oil painting circa 1950 (artist unknown) 90007 becoming brittle and cracking over time. 90003 90002 What are the consequences of these different chemistries? Oil paints become somewhat brittle as they cure, and the ongoing chemical changes will gradually increase this brittleness as they age. As a result, oil paints are increasingly vulnerable to cracking over time. Mayer’s compendium on artist materials [4] lists seven expedients that will minimize the tendency to cracking, including proper preparation of substrates, painting fat over lean and avoiding painting fast drying colors (e.g. burnt umber) over slow drying colors (e.g. alizarin crimson). Nonetheless, the author has observed that many, if not most, 100+ year-old oil paintings in several leading museums have cracked, as have some relatively recent paintings. Thick films on flexible grounds, such as canvas, appear especially vulnerable. 90003 90002 At normal indoor temperatures, acrylic paintings are much more flexible than oils. Thus, newly painted acrylics are expected to resist cracking better than newly painted oils in these conditions, even in very thick films.At low temperatures, however, the acrylics become brittle. Typically their flexibility drops sharply at temperatures a bit above freezing, say between 0 and 15 oC (32 to 59 oF), depending on the color, the composition of the acrylic, and the relative humidity. [5] Oils also become more brittle when cold, but embrittlement occurs at temperatures below freezing. Mecklenburg et.al. have shown that significant drops in temperature from 23o C down to below freezing at very low humidity can create stresses in a fairly young 13 year old oil paint film that will exceed its breaking point.[6] Both types of paintings should be handled very carefully when they are cold, especially when the air is dry. [7] 90003 90002 Do artists still work in freezing garrets? If so, oils will work better. The temperature at which the paint is applied is more of a concern with acrylics than with oils. Acrylic house paints should not be used when the temperature is below about 5 oC (about 40 oF) or when the temperature is expected to fall below this level for 4 to 8 hours after the paint was applied.The reason is that strong, coherent films can not form at low temperatures, and even if the film later becomes warm, it will never recover. Acrylic artist paints are similar. To be on the safe side, they should be used only at temperatures above 10 oC (about 50 oF), and the painting should be kept above this temperature for several days after it has dried. [8] Acrylics painted and dried under cold conditions may look OK, but the films will be less durable and more vulnerable to cracking. Oils, on the other hand can be used at freezing temperatures or below.90003 90002 While newly painted acrylics will be more crack resistant than newly painted oils, the question is how the film properties change with age. We know a lot about acrylic films for other applications (briefly described in Section 9) but only a few published studies concern artist paints. In one series of studies, Prof. Whitmore and Dr. Colaluca at Carnegie Mellon University attempted to accelerate the deterioration of «Liquitex Acrylic Gloss Medium» films. [9,10] 90005 «While films of Liquitex gloss medium did photo-oxidize upon exposure to ultraviolet light, the material generally demonstrated the remarkable photochemical stability associated with this class of acrylic polymers.In comparison to the mechanical property loss under UV-B exposure, tensile strength loss under UV-A lamps would have been observed only after about 200 days, a dose of near ultraviolet light equivalent to about 5,000 ‘museum years.’ «90010 [8 , 9] Encouraging as this conclusion is, one must recognize that accelerated testing of paints is notoriously unreliable, especially when the acceleration factor is high. In this study the factor was about 8700: 1 — one museum year = about one hour of accelerated testing.Furthermore, many paintings are subjected to rough handling and exposed to light, humidity, and temperature fluctuations more severe than they would encounter in a museum. 90003 90079 90002 Shown above is a Fluid Acrylic Naphthol Red Light film forming at ambient temperatures (left), at temperatures 38 ° — 40 ° F (center) and at 26 ° — 28 ° F (right). This clearly demonstrates acrylics ‘inability to form coherent films below 49 ° F. 90003 90002 Oils that have cracked are vulnerable to other problems.If adhesion is less than excellent, flakes of cracked films may delaminate. Even if the film remains attached to the ground, the cracks may open up, making them highly visible. Cracked oils may also suffer cupping, defined by Mayer as 90005 «concavities or depressions that sometimes exist inside the boundaries of a network of cracks.» 90010 [11] 90003 90002 90006 4. Yellowing 90007 90009 90007 Oils tend to be slightly yellow from the beginning, and the oxidation processes that cause hardening also cause additional yellowing.Different oils yellow to different degrees. Exposure to certain common chemicals, such as ammonia vapor from household cleaners, can make yellowing worse. There have been many efforts, spanning at least a century, to solve the yellowing problem. None have been completely successful. A detailed study of the chemical causes of yellowing by Professors Mallegol, Lemaire and Gardette at University Blaise Pascal in France concluded 90005 «Yellowing must therefore be considered as an unavoidable characteristic of drying oils and this must be kept in mind by users.»90010 [12] 90003 90002 There is divided testimony in the literature as to how badly oils yellow. Crook and Lerner [13] state that 90005 «Linseed oil … has been used most widely due to its relatively rapid drying time. However, this is unfortunately accompanied by a tendency to yellow with age. Other, less yellowing oils have sometimes been used, especially for white paints and other light colors. » 90010 90003 90002 On the other hand, many artists agree with Mayer when he ігри [14] says that yellowing 90005 «… concerns only clear oil films and the use of oils in techniques other than normal oil painting» and that «correctly executed oil paintings do not turn yellow.»90010 Perhaps the difference of opinion results from differing views as to how much yellowing is tolerable. This author’s observations in museums suggest that yellowing is discernable in whites and pastel colors of older oil paintings, although it is hard to tell how much of the problem is the paint and how much is the varnish. Franz Hals ‘lacework may look white, but not when it is compared to a piece of white paper. The behavior of oil household paints suggests that the problem is significant.The whites gradually turned yellow and then tan when used indoors. This is one of the main reasons such paints have become almost obsolete in architectural applications. 90003 90002 The acrylic polymers used in high quality artist paints are almost colorless when they are first used, and with age they yellow very slowly under normal conditions. The very low tendency to yellow is the main reason acrylics are candidates for use as varnishes. Whitmore and Colaluca [15] reported slight yellowing of the acrylic medium they studied.Levison saw «no perceptible yellowness in any of the acrylic specimens [16].» Based on well established behavior of architectural and artist paints, it is safe to say yellowing of acrylics is much less of a problem than it is with oils. 90003 90002 90006 5. Dirt pick up and cleanability 90009 90003 90002 Oils have a clear advantage to acrylics regarding dirt pickup. Cleanability of oils is much more complicated, however [17]. Acrylic paint films are slightly porous and are softer than oil paint films, making dirt more likely to stick to them.Polymer molecules in the acrylics are at most only slightly cross-linked, making the films hard to clean because solvents and cleaners can degrade the acrylic surface. In theory, this problem could be overcome by increasing the cross-linking level in acrylics. Researchers have found practical ways to cross-link acrylics for other applications, e.g. varnishes for wood cabinets. Introduction of such technology into artist paints is possible but would require great caution because of the possibility of undesired effects on other properties and the uncertain effect on long-term durability.Research is also underway to define the best methods of cleaning unvarnished acrylics. (See article on Page 11 regarding the Samuel Golden Fellowship for Research into Modern Painting Materials at the National Gallery of Art in Washington, DC) The tendency to pick up dirt can also be reduced by varnishing acrylic paintings, but many painters prefer the appearance of the unvarnished surface. 90003 90110 90002 Above is an example of a dirty acrylic film showing two types of cleaning methods. Pictured left to right is the dirty acrylic film, the dry cleaning method and a wet cleaning method.90003 90002 90006 6. Will the nose fall off? 90009 90003 90002 Another aspect of durability is adhesion of the paint to its substrate. As Mayer points out, 90005 «linseed oil is not a strong adhesive» 90010 and the same could be said of the acrylic binders used in artist paints. What is most important is that with proper use both oils and acrylics are capable of giving fully satisfactory adhesion, and with improper use they are likely to fail. As with most paints, the most critical factor in obtaining good adhesion is to properly prepare the substrate ( «the ground»).Gottsegen extensively discussed grounds for oil painting. [18] With oils, canvases must be undercoated with a ground that can protect the canvas from the oil. With acrylics, undercoating is desirable but not essential. Artists use many substrates, and recommendations for how to prepare them are published. 90003 90002 Overpainting artist oils with artist acrylics is definitely bad practice. The surface of hardened oil paint does not have «tooth.» It is too hard and often too shiny to afford good adhesion by acrylics.Paints stick better to rough surfaces than to smooth ones if other factors are equal. The roughness may be visible to the naked eye or microscopic. Either way, roughness increases the surface area upon which the attractive forces of the paint to the ground can act. On very rough surfaces, the paint may penetrate into recesses; then when it hardens mechanical interlocking, analogous to dovetail joints, can strongly enhance adhesion. Thus, rough surfaces are said to have «tooth.» Primers usually have low gloss, evidence of microscopic tooth.Most acrylics have more tooth than most oils, and overpainting acrylics with oils has a better chance to work, but the artist should be aware of potential problems. 90003 90002 90006 7. Will colors fade? 90009 90003 90002 Fading has been a problem for centuries. The stability of colors in both acrylic and oil paints depends primarily on the lightfastness of the pigments used. Most pigments used in contemporary artist paints are selected from lists of about 115 pigments that are established by ASTM International (formerly The American Society of Testing Materials) to be lightfast in acrylics [19a] and in oils [19b].The lists are somewhat different to avoid alkaline pigments in oils and pigments that could be affected by water in acrylics. Artist paints are labeled with the lightfastness grade of the pigment; only pigments graded I (excellent) or II (very good) are considered suitable for archival paints. Certain special colors, such as fluorescent colors, are not lightfast. Use of lightfast pigments makes severe pigment-related color changes very unlikely for paintings that are kept indoors. Artists should be aware, however, that certain special colors, such as fluorescent colors, are not lightfast.90003 90129 90002 The GOLDEN Lab conducts exposure testing to be able to evaluate new materials for durability. This photo shows the test fence at Golden Artist Colors, Inc. 90003 90002 90006 8. What can we learn from other types of paints? 90009 90003 90002 Most (not all) artwork is kept indoors where it is protected from most of the damaging UV light in sunlight and from weather extremes. Window glass filters out the most destructive UV light in sunlight. It is widely accepted in the paint industry that indoor exposure is much less damaging to paint than outdoor exposure.In addition, it is widely assumed that paint that is durable outdoors will be very long-lived indoors. 90003 90002 The binders of exterior house paints evolved from vegetable oils to alkyd resins (starting in the 1930s) to acrylics (starting in the 1950s). It is almost universally recognized that each step was a major advance in outdoor durability. The acrylics used in contemporary artist paints are chemically similar to those used in high-quality house paint. Oil and alkyd paints (alkyds are synthesized from oils) are more vulnerable than high quality acrylics to the enemies of paint — ultraviolet radiation, water and heat.A tour of older neighborhoods will show examples of house paints that are severely cracked. These are almost always oil or alkyd paints that have become so brittle that they can not accommodate expansion and contraction caused by temperature fluctuations and moisture. In contrast, acrylic house paints retain their flexibility for many years. By now, over 80% of exterior paints used in the U.S. are water-borne «acrylics.» In this context «acrylics» means polymers that contain some acrylic monomer, but some also contain less expensive monomers such as styrene and vinyl acetate; the highest quality paints are 100% acrylic.Better durability is a major reason for acrylics ‘their popularity, but not the only reason. Soap and water clean-up and reduced organic solvent evaporating into the environment are also important advantages of acrylics. The alkyds that are still used as exterior house paints are used mainly as primers (where they are not exposed to direct sunlight) and by contractors who like the superior one-coat hiding of alkyds or who want to paint at temperatures near or below freezing ( see section 2). 90003 90002 Most paints for home interior walls are based on poly (vinyl acetate) ( «PVAC»).PVAC is used indoors because it is less expensive than acrylics, but it lacks satisfactory durability outdoors. PVAC based paints have been used by artists since the 1930s, but their usage appears to have been rather limited. [20] PVAC paints are used in art restoration and conservation. According to Horie, [21] attempts to remove them are sometimes quite successful and sometimes not. As media for archival painting they are almost certainly inferior to acrylics. 90003 90002 Automotive paints evolved from oils to nitrocellulose lacquers to alkyds to acrylics.Again, each step improved durability. The days are long past when cars had to be waxed and polished frequently to keep their shine. Introduction of acrylics made durable metallic car paints and durable clearcoats possible. Modern acrylic car paints are expected to retain good appearance for 10 years or more, even when the cars are driven and parked outdoors in harsh environments such as south Florida or Arizona. Acrylic car paints and acrylic artist paints both depend on the acrylic backbone for their durability.[22] 90003 90002 90006 9. Are all acrylics the same, and are they really acrylics? 90009 90003 90002 Learner at the Tate Gallery in London used sophisticated instruments to analyze synthetic paint binders used in 20th Century artist paints. [23] He studied paints on a large number of modern paintings, including paintings by many well-known artists. Learner found 100% acrylic co-polymers on some paintings. He also found acrylic / styrene co-polymers, acrylic / (vinyl acetate) co-polymers, poly (vinyl acetate), and vinyl acetate / vinyl neodecanoate co-polymers.Any of these latter types could easily be mistaken by artists for 100% acrylics, since they are all based on emulsion polymers of similar physical appearance. Among the paints that were 100% acrylics, Learner found two types of co-polymers: [p (EA / MMA)] and [p (nBA / MMA)] (see Glossary). 90007 The author has studied and researched a wide variety of paints for 35 years, and has recently researched artist paints [24]. Based on this experience he has developed opinions about what types of chemistry are most likely to perform well as archival artist paints: 90003 90039 90040 Learner identified many kinds of polymers that have been used in artist paints.Two kinds, 100% Acrylics and certain polyurethanes, are expected to be the most durable. Based on their performance in architectural paints, 100% acrylics are preferable to acrylic / (vinyl acetates), acrylic / styrenes, and, especially, poly (vinyl acetates). 90041 90040 Unfortunately, in the commercial paint industry it has been common to represent acrylic / styrenes and acrylic / (vinyl acetates) as «acrylics.» It is not known to the author whether this practice spread to the artist paint field. 90041 90040 Among 100% acrylics, [p (nBA / MMA)] is expected to be superior to [p (EA / MMA)].Experience with house paints has shown that [p (nBA / MMA)] based paints weather better than [p (EA / MMA)] paints. 90041 90044 90002 Quoting Learner’s paper [23]: 90007 90005 «Although both types of pure acrylic emulsion are utilized in current (artist) paint formulations, over the years there has been a gradual increase in use of p (nBA / MMA), as the production of many p (EA / MMA) emulsions has been terminated. This is because the principal commercial use of these emulsions, namely exterior house paints, requires a hydrophobic material and in general the [p (nBA / MMA)] copolymers show a superior hydrophobicity.Out of 10 brands of acrylic emulsion paint obtained in 1993, [p (nBA / MMA)] was found to be the binder in four of them, and most new formulations produced since then have been based on this emulsion. » 90010 90003 90002 Combining the author’s opinions (unproven) with Learner’s findings (established facts), we can conclude that: 90003 90039 90040 Many types of emulsion polymers and co-polymers have been used in artist paints. 90041 90040 In the early decades of «acrylic» paint use, it is likely that many artists used «acrylics» that were inferior to modern acrylics and were, perhaps, not acrylics at all.90041 90040 The acrylics available today from reputable suppliers are probably better from the standpoint of longevity than some of those in use 25-50 years ago. 90041 90040 Information available today indicates that artist paints made with [p (nBA / MMA)] co-polymers are very likely to afford long-lived paintings. 90041 90044 90002 90006 10. What does practical experience tell us? 90009 90003 90002 The most reliable way to assess the durability of paints is to evaluate them in actual service in the field.That is why car manufacturers send out survey teams to inspect cars that have been in use. They can observe cars in the field for their entire lifetimes, and they can tell from the Vehicle Identification Number (VIN) of the car exactly what day the car was painted and what paint was used. Artist paint manufacturers are not so lucky. Often, it is not known what brands of paint, ground, and canvas were used in a painting made twenty or fifty years ago, although their chemical types can be established by chemical analysis.90003 90002 So, what do we know about artist acrylics in service? Most important, the vast majority of acrylic paintings made since the introduction of acrylics are holding up well, including many that were made with paints that were probably inferior to the acrylics available today, as explained in Section 9. Acrylics can crack, especially if they are roughly handled when they are cold [25]. 90003 90002 Despite the good record of acrylics so far, some artists and conservators remain concerned about the long-term durability of acrylics because of their relatively short history.After all, acrylics have been used only for about 70 years and paints based on acrylic dispersions for about 50 years, while oils have been around for 500 years. 90003 90002 Such concerns have been fueled by a few well-publicized [26-29] failures of «acrylic» paintings by major artists. The failures of acrylics reported in the popular press have been variously described as fading, flaking, cracking, and crumbling. Beyond that, there is little information available that would enable a rigorous judgment of the causes of failure.One can only speculate based on knowledge and experience: 90003 90039 90040 The most likely cause of fading is use of pigments that are not lightfast; this statement applies equally to oils and acrylics. 90041 90040 The most likely cause of flaking (presumably loss of adhesion) is painting over dirty or improperly prepared surfaces. Many other causes are possible, including poorly formulated paint. 90041 90040 The most likely causes of cracking and crumbling are the paint itself and / or bad painting technique.As discussed above, acrylics can certainly crack, but on the whole they are less vulnerable to cracking than oils. 90041 90040 Many of the paintings attributed to acrylic (including Rothko’s Harvard Murals) were done in other media. [28] 90041 90044 90002 90006 Summary 90009 90003 90002 Fears have been expressed that there might be wholesale failures of acrylic paintings after they have aged longer. Acrylics have not been around long enough, and accelerated testing is not reliable enough to definitively prove that this will not happen.90003 90002 But to this author, it seems far more likely that acrylic paintings will prove very long lived, especially if they are properly painted with high quality contemporary materials and well cared for. The weight of available evidence indicates that acrylics will prove to be more durable than oils, and oils have been around for 500 years. 90003 90002 90006 Acknowledgements 90009 90003 90002 The author is grateful to the National Science Foundation for support of research on artist paints under grant number 9903813, «Artist Paints with Improved Durability.»Helpful comments from the artists ‘point of view were provided by Professors Diana Pancioli and Roy Johnston of Eastern Michigan University. Valuable insights were provided by Mark Golden and Jim Hayes of Golden Artist Colors, Inc. Jodi O’Dell, also of Golden Artist Colors, Inc., provided excellent editorial assistance. 90003 90002 1 www.societyofcanadianartists.com/tips/acrylics June 30 2004 90007 2 www.artandantiques.net July 7, 2004. 90007 3 www.wetcanvas.com/forums August 11, 2003. 90007 4 R.Mayer, The Artist’s Handbook of Materials and Techniques, 5th Edition, updated by S. Sheehan, Viking, New York, 1991, pp. 209-211. 90007 5 J.D. Erlebacher, M.F. Mecklenburg, and C.S. Tumosa, Polym. Prepr., 33 (2) (1992) 646-647. 90007 6 M. Mecklenburg, C.S. Tumosa and M.H. McCormick-Goodhart, «A General Method for Determining the Mechanical Properties Needed for the Computer Analysis of Polymeric Structures Subjected to Change in Temperature and Relative Humidity,» Journal of the American Institute for Conservation, (1994), Vol.33, No. 2, Article 7, pp. 153-170. 90007 7 Anon., «A special feature on acrylic and other synthetic media paintings, Part 3: Acrylics — inherent susceptibility to cracking,» McKay Lodge Conservation Report, 1991, No. 3, 16. 90007 8 www.goldenpaints.com 90007 9 P.M. Whitmore and V.G. Colaluca, Studies in Conservation, 40 (1995) 51-64. 90007 10 P.M. Whitmore, V.G. Colaluca, and E Farrell, Studies in Conservation, 41 (4) (1996) 250-255. 90007 11 R. Mayer, op. cit., p. 503. 90007 12 J. Mallegol, J. Lemaire, and J-L Gardette, Studies in Conservation, 46, (2001) 121-131.90007 13 J. Crook and T. Learner, The impact of modern paints, Watson-Guptill Publs., New York, 2000. 90007 14 R. Mayer, op. cit., p. 468. 90007 15 P.M. Whitmore, V.G. Colaluca, and E Farrell, Studies in Conservation, 41 (4) (1996) 250-255. 90007 16 Henry W. Levison, «Yellowing and Bleaching of Paint Films,» Journal of the American Institute for Conservation, (1985), Vol. 24, No. 2, Article 2 pp. 69-76. 90007 17 Kenneth R. Sutherland, Solvent extractable components of oil paint films, 1, (2001) 90007 18 Mark David Gottsegen, The Painter’s Handbook, 1993, p.41 90007 19a. Anon., ASTM D 5098. b. Anon., ASTM D 4302. 90007 20 J. Crook and T. Learner, op. cit., pp. 21-24. 90007 21 C. V. Horie, Materials for Conservation, Reed, London, 1987, pp. 92-96. 90007 22 Other features of their chemistry are different. Car paints are highly cross-linked, and in the factory they are cured by baking at temperatures above 120 oC (250 oF). 90007 23 T. Learner, Studies in Conservation, 46 (2001) 225-241. 90007 24 «Artist Paints — An overview and preliminary studies of durability,» Jones, F.N .; Mao, W .; Ziemer, P.D .; Xiao, F., Prog. Org. Coatings, 2004, accepted for publication. 90007 25 D.W. Grattan, Saving the Twentieth Century: The Conservation of Modern Materials, (1993) 411-438. 90007 26 E.B. Wyer, «Flaky art; modern masterpieces are crumbling, «New York, (January, 1998) 25. 90007 27 C. Hume,» ‘Cracked’ painting row shakes art world, «The Toronto Star, (May 24, 1992). 90007 28 C. Lees and R. Palmer, «Cracking paint ruins modern masterpieces,» The London Times, (March 29, 1992).90007 29 P. Recer, «20th-Century art fails the test of time,» Toronto Globe & Mail, (September 1, 1992). 90003 .90000 How to paint with acrylic washes 90001 90002 90003 90002 Learning how to draw and paint takes time, knowledge and patience. But, there are a number of drawing and art techniques you can adopt to help you along the way. Acrylics are a very flexible medium: they can be used direct from the tube to create thick dense colour, or, as we’ll do here, watered down and layered to give depth and an almost ethereal quality. 90003 90002 I try to embrace a spontaneity in my work, and the drips and splashes of watered-down acrylic lend themselves well to that process — even accidents that seem disastrous at the time.Let me take you through my process of painting when working with acrylic paints. 90003 90008 01. Start with sketchbooks and ideas 90009 90002 90003 Sketching allows room to explore your idea as it progresses 90002 My work always starts in the sketchbook. It’s a risk-free environment to explore ideas and hopefully surprise yourself. I’m a constant doodler and I try and keep things as loose as possible throughout this stage, allowing for room to explore the idea as it progresses. 90003 90008 02.Move the sketch onto paper 90009 90002 90003 Really get a feel for the piece as you transfer the drawing 90002 I prefer to redraw my sketch, rather than transferring it using a light box or projector. It takes longer but retains the spontaneity of the original, as well as letting the idea develop further. I probably spend too long on this stage, but it does help me get a feel for the piece. This drawing also acts as an underpainting. 90003 90008 03. Prepare for the initial wash 90009 90002 90003 Using a mop brush, cover the entire surface with clean water 90002 Using a mop brush, I cover the entire surface with clean water, preparing it for the initial wash.Then I mix up the initial colour. I mix a lot of paint — in this case Prussian blue, Hookers green and a touch of Phthalo turquoise — which gives the colour a little more depth, using a lot of water to thin it down. 90003 90008 04. Apply the first wash 90009 90002 90003 Things can look a little messy at this stage — but I enjoy the spontaneity! 90002 I then load my mop brush with a lot of paint and wash it onto the wet paper, working across the paper and allowing the water to carry the paint down the surface.Things can look a little messy at this stage, but I enjoy the spontaneity, seeing how the paint goes down, and it will be worked on and refined later. 90003 90008 05. Work with the wash 90009 90002 90003 While it’s still wet, get a feel for highlights by lifting paint off with a clean / dry mop brush 90002 While it’s still wet, I start to work into the image, getting a feel for highlights by lifting paint off with a clean, dry mop brush. I also use a water spray from a garden centre to wash areas if I want to blend paint or remove it altogether.I repeat this process, gradually building layers of colour. 90003 90008 06. Build colour and tone 90009 90002 90003 Each layer is a very slight development on the last, creating denser colour and tone 90002 Each layer is a very slight development on the last, creating denser colour and tone. As the process continues I can refine areas more. When I want to create a harder edge I will paint an area with water first and then apply the wash, letting the paint run into the water and along the edge.90003 90008 07. Blend different shades 90009 90002 90003 Working wet on wet produces subtle blends 90002 Working wet on wet produces subtle blends. I enjoy the softness this gives, but if I want to stop the paint running into an area I’ll use a hair dryer to dry areas as I’m working. I do not worry about the drips — they’re part of the fun — but if they do interfere with something I will lift them with the brush or wash them off with the water spray. 90003 90008 08. Add detail 90009 90002 90003 Use a selection of long-handled brushes to start to establish darker areas, enhance contrast and bring out key forms and shapes 90002 I now want to give the painting some form.I’ve aimed for an overall mid-tone at this stage and now I’ll work with a denser mix of paint, using a selection of long-handled brushes to start to establish darker areas, enhance contrast and bring out key forms and shapes . 90003 90008 09. Introduce colour 90009 90002 90003 Do not worry about final hues at this stage, just lay down a ground colour 90002 Up until this point I’ve been working on tone and form. Now I want to add colour. Still working with thin washes, first I add a mix of Yellow ochre, muted with Buff titanium, to the figures.At this stage I’m not worried about the final hues — I’m just laying down a ground colour. 90003 90008 10. Keep it loose 90009 90002 90003 It’s worth noting that colour looks strong when first applied, it’ll be much paler when it dries 90002 I then add a wash of Alizarin crimson mixed with Quinacridone burnt orange to the flowers area. I’m not painting the flowers as such, rather adding colour areas that I can play with later. It’s also worth noting that however strong the colour looks when you first apply it, it’ll be a lot paler once it dries.90003 90008 11. Layer washes 90009 90002 90003 It’s at this stage that the painting starts to gain its depth 90002 From now on it’s really a matter of repeating the process, alternating between gradually building colour and tone with additional washes and working on areas of detail . It’s at this stage that the painting starts to gain its depth. Colours become deeper, shadows grow darker, and detail and form are more defined. 90003 90008 12. Evaluate the painting 90009 90002 90003 A long-handled flat brush helps shape the painting 90002 I continue to step back and evaluate.I aim to create a flow through the piece, but the composition seems to be missing something to lead the eye out, so I’m adding detail to the bottom corner. I shape it with a long-handled flat brush but purposefully keep it looser than the more defined flowers — this will create depth, helping to foreground detail. 90003 90008 13. Refine details 90009 90002 90003 Now you are able to focus on detail 90002 Now I’m able to focus on the detail. I tend to move from my easel to a flat surface. I like to be ‘over’ my painting at this stage.It’s now that the painting starts to come to life, as I’m able to focus on the fine details that create character. 90003 90008 14. Revisit undefined areas 90009 90002 90003 It’s time to revisit the areas to which rough colour was previously applied 90002 It’s time to revisit areas to which I’ve previously applied rough colour. I’m now able to go in and work on them, adding refinement, detail and depth. 90003 90008 15. Appraise and finalise 90009 90002 90003 The final stage is to step back again and look for any areas that need tightening up 90002 The final stage is to step back again and look for any areas that need tightening up and any opportunities for additional detail to add narrative to the painting.Here I feel that some thin bones would add context to the bird skull. 90003 90002 90099 This article was originally published in ImagineFX, the world’s best-selling magazine for digital artists. 90100 90099 Subscribe now 90100 90099. 90100 90003 90002 90107 Read more: 90108 90003 .90000 Basic Acrylic Painting Techniques- How to Paint an Apple 90001 90002 About Acrylic Paint 90003 90004 Acrylic paint is a relatively new medium in the world of art. It has been around for just over a half a century. Despite it’s «newness», acrylic paint has quickly become a popular art making medium. 90005 90004 Acrylic paint is less dangerous than oil paint because it uses water instead of toxic solvents. When dry, acrylic paint can have some of the same visual characteristics as oil paints.90005 90004 90009 90005 90004 Application methods vary for acrylics just as they do for other painting mediums. Every artist will find an approach that best suits the effects that they are after in their own painting. It is a good idea to experiment to find the process that best suits you. 90005 90004 In this lesson, we’ll look at creating a small still life painting of an apple by layering colors on the surface. We’ll begin with an underpainting to develop the values ​​before moving on to layering the local colors of the apple.90005 Recommended Materials 90004 (Some of the following links are affiliate links which means we earn a small commission if you purchase at no additional cost to you.) 90005 90002 A Look at The Palette 90003 90004 When painting with acrylics, I prefer to use a disposable palette, in this case — palette paper. Acrylics dry incredibly fast and have the potential of creating quite a mess on a plastic palette. A disposable palette can be thrown away after the painting process and makes for easy clean up.90005 90004 Colors chosen are determined before painting begins by analyzing the subject or the photo reference. In most circumstances, additional pigments will be added to the palette during the painting process. 90005 90004 90024 90005 90004 For this demonstration, I am using several pigments. I like to arrange the paints on the palette with enough space for mixing in between them. 90005 90004 90029 90005 90004 While the subject that you paint will dictate the actual pigments that are used, it’s a good idea to try and limit them as much as possible.Limiting your palette will encourage harmony and unity in the work. 90005 90002 Step By Step Process 90003 90004 A blank white canvas might seem like a great place to start, but in many cases it’s a good idea to start with a bit of color. Adding a bit of color to the surface creates a nice starting point for judging values ​​due to contrast. This practice is often referred to «as creating a ground». 90005 90004 The «ground» can be any color that you like, but it is advisable to choose a color that may accentuate the finished painting.In many cases, the ground will still be visible through the subsequent brush strokes that are applied. 90005 90004 In this example, a neutral ground is created and evenly applied to the canvas. A mixture of Raw Umber and Titanium White is used to mix the neutral ground. 90005 90004 After the ground has dried, a pencil sketch is applied. A softer graphite pencil is used to draw the contour lines of the shape of the apple and to «map out» the areas of value and color changes. 90005 90004 90044 90005 90004 Some artists prefer to start painting the local colors (observed colors) at this point.This approach is perfectly acceptable as long as the values ​​of the colors are addressed at a later stage. However in this example, we’ll start by addressing the values ​​by painting an underpainting. The underpainting allows us to begin to establish the values ​​of the painting early in the process. 90005 90004 A mixture of Payne’s Gray and Burnt Umber are used to apply the darker values. The color is thinned a bit with water to address mid tones. White is mixed with the ground mixture to address the lighter values.In this case, the underpainting is «loose» and does not address all of the observed values. 90005 90004 90051 90005 90004 At this point, we’re ready to start addressing the local colors that are observed. You may start with any section of the painting that seems natural to you because acrylics layer easily and dry very quickly. In this example, the areas of yellow-green are addressed first. A mixture of Cadmium Yellow Light, Prussian Blue, Indian Yellow Hue, and White is used. 90005 90004 90056 90005 90004 As colors are added with the brush, the form of the object is considered.Strokes are pulled along the cross contours of the apple. These subtle, directional lines help to inform the viewer of the form. 90005 90004 The layering of color continues with the sections of red on the apple. A mixture of Alizarin Crimson and Cadmium Red Light is used. For areas of darker value, Burnt Umber and Payne’s Gray are added. For lighter values, Titanium White is mixed. 90005 90004 90063 90005 90004 With each layer that is added, the colors become more complex. Adjustments to the value and concentration of the mixtures are made with each application.As larger areas of color are added, details can be developed. 90005 90004 90068 90005 90004 The area of ​​cast shadow behind the apple is strengthened with a mixture of Payne’s Gray and Burnt Umber before being layered over with a mixture of White and Raw Umber. 90005 90004 90073 90005 90004 With a few final touches, the painting is completed. 90005 90002 A Bit More On Acrylic Painting 90003 90004 Like all paints, acrylic paint is made up of three general ingredients (more exist but generally fall into one of these categories) -pigment, solvent, and binder.The pigment is the color and is generally universal in all different types of paints. 90005 90004 Solvent is what thins the paint. Water is typically used as the solvent for acrylic painting. 90005 90004 Binder is the material that holds the pigment together and allows the paint to be spread over a surface. Acrylic paint has a binder of acrylic polymer emulsion and dries quickly to create a waterproof surface. It can also can be used as a glue or as an image transfer medium. Acrylics can be matte finish or gloss.Matte acrylics dry to a dull sheen while gloss acrylics are shiny. 90005 90004 Acrylics can be applied with brushes, palette knives, or really anything at all. In my experience, nylon brushes work best with acrylic paint-although any type of brush will work. It is especially important to keep your brushes clean, as acrylic paints will dry quickly and ruin a brush. 90005 90002 Surfaces For Acrylic Painting 90003 90004 Acrylics can be applied to almost any surface. Artists mostly use canvas, watercolor paper, illustration board, gessoed masonite, or other papers to paint on-although any surface is fair game.90005 90004 Acrylic paints are resistant to UV light making them a suitable choice for outdoor applications. Acrylic paint also dries to create a waterproof surface that is impervious to many types of liquids. 90005 90004 Acrylic paints can be used with a variety of different acrylic mediums that can change the characteristics of the paint. Some mediums make the paint thicker for impasto effects, while some make the paint more transparent for glazing techniques. Others change the texture of the paint.Experiment with different mediums to find out which ones suit you best. 90005.