Acrylic Paint!

Acrylic paint is fast drying paint containing pigment suspension in acrylic polymer emulsion. Acrylic paints can be diluted with water, but become water-resistant when dry. Depending on how much the paint is diluted (with water) or modified with acrylic gels, media, or pastes, the finished acrylic painting can resemble a watercolor or an oil painting, or have its own unique characteristics not attainable with other media.

History

Leonard Bocour and Sam Golden between 1946 and 1949 had invented a solution acrylic paint under the brand Magna paint. A waterborne acrylic paint called «Aquatec» would soon follow. Otto Rohm invented acrylic resin, which quickly transformed into acrylic paint. Acrylics were first made commercially available in the 1950s. These were mineral spirit-based paints called Magna. In 1953, the year that Rohm and Haas developed the first acrylic emulsions, Jose L. Gutierrez produced Politec Acrylic Artists Colors in Mexico and Permanent Pigments Co of Cincinnati Ohio produced Liquitex colors. These two product lines were the very first acrylic emulsion artists paints. Water-based acrylic paints were subsequently sold as «latex» house paints, although acrylic dispersion uses no latex derived from a rubber tree. Interior «latex» house paints tend to be a combination of binder (sometimes acrylic, vinyl, pva, and others), filler, pigment, and water. Exterior «latex» house paints may also be a «co-polymer» blend, but the very best exterior water-based paints are 100% acrylic, due to elasticity and others, but 100 percent acrylic resins cost double as much as vinyl and PVA (polyvinyl acetate) is even cheaper, so paint companies make many combinations of them to match the market.

Soon after the water-based acrylic binders were introduced as house paints, artists and companies alike began to explore the potential of the new binders. Water-soluble artists’ acrylic paints became commercially available in the 1950s, offered by Liquitex, with high-viscosity paints similar to those made today becoming available in the early 1960s. In 1963, Rowney (now part of Daler-Rowney Ltd since 1983) was the first manufacturer to introduce an artist’s acrylic color in Europe, under the brand name Cryla.

TECHNIQUES

Main article: Acrylic painting techniques

Acrylic artist paints may be thinned with water and used as washes in the manner of watercolor paints, but the washes are not re-hydratable once dry. For this reason, acrylics do not lend themselves to color lifting techniques as do gum arabicbased watercolor paints.

Fluorescent acrylic paints lit by UV light. Paintings by Beo Beyond

Acrylic paints with gloss or matte finishes are available, although a satin (semi-matte) sheen is most common; some brands exhibit a range of finish (e.g., heavy-body paints from Golden, Liquitex, Winsor & Newton and Daler-Rowney).Politec acrylics are fully matte. As with oils, pigment amounts, and particle size or shape can naturally affect the paint sheen. Matting agents can also be added during manufacture to dull the finish. The artist can mix media with their paints and use topcoats or varnishes to alter or unify sheen if desired.

When dry, acrylic paint is generally non-removable from a solid surface. Water or mild solvents do not re-solubilize it, although isopropyl alcohol can lift some fresh paint films off. Toluene and acetone can remove paint films, but they do not lift paint stains very well and are not selective. The use of a solvent to remove paint may result in removal of all of the paint layers, acrylic gesso, etc. Oils can remove acrylic paint from skin.

Only a proper, artist-grade acrylic gesso should be used to prime canvas in preparation for painting with acrylic (however acrylic paint can be applied to raw canvas if so desired without any negative effect or chemical reaction as would be the case with oils). It is important to avoid adding non-stable or non-archival elements to the gesso upon application. However, the viscosity of acrylic can successfully be reduced by using suitable extenders that maintain the integrity of the paint film. There are retarders to slow drying and extend workability time and flow releases to increase color-blending ability.

Painters and acrylic

Prior to the 19th century, artists mixed their own paints which allowed them to achieve the desired color, thickness, and to control the use of fillers, if any. While suitable media and raw pigments are available for the individual production of acrylic paint, due to the fast drying time and other technical issues, hand mixing may not be practical.

Acrylic painters modify the appearance, hardness, flexibility, texture, and other characteristics of the paint surface using acrylic media or by simply adding water. Watercolor and oil painters also use various media, but the range of acrylic media is much greater. Acrylics have the ability to bond to many different surfaces, and media can be used to adjust their binding characteristics. Acrylic can be used on paper, canvas and a range of other materials. However, their use on engineered woods such as medium-density fibreboard can be problematic because of the porous nature of those surfaces. In these cases it is recommended that the surface should be previously sealed with an appropriate sealer. They can be applied in thin layers or washes creating effects that resemble watercolors and other water-based media. They can also be used to build thick layers of paint: gel and molding paste media are sometimes used to create paintings with relief features that are literally sculptural. Acrylic paints are also used in hobbies such as: train, car, house, and human models. People who make such models use acrylic paint to build facial features on dolls or raised details on other types of models.

Acrylic paints are the most common paints used in grattage. Grattage is a surrealist technique that became popular with the release of acrylic paint. Acrylics are used for this purpose because they easily scrape or peel from a surface.

Differences between acrylic and oil paint

The vehicle and binder of oil paints is linseed oil or another drying oil, whereas water serves as the vehicle for an emulsion (suspension) of acrylic polymer that is the binder in acrylic paint. Thus, oil paint is said to be «oil-based», while acrylic paint is «water-based» (or sometimes «water-borne»).

The main practical difference between most acrylics and oil paints is the inherent drying time. Oils allow for more time to blend colors and apply even glazes over underpaintings. This slow drying aspect of oil can be seen as an advantage for certain techniques, but in other regards it impedes the artist trying to work quickly. The fast evaporation of water from regular acrylic paint films can be slowed with the use of acrylic retarders. Retarders are generally glycol or glycerin-based additives. The addition of a retarder slows the evaporation rate of the water.

Oil paints may require the use of solvents such as mineral spirits or turpentine to thin the paint and clean up; these generally have some level of toxicity and are often found objectionable. (Relatively recently, water-miscible oil paints have been developed for artists’ use.) Oil paint films can become increasingly yellow and brittle with time and lose much of their flexibility in a few decades. Additionally, the rules of «fat over lean» must be employed to ensure the paint films are durable.

Oil paint has a higher pigment load than acrylic paint. As linseed oil has a smaller molecule than acrylic, oil paint is able to absorb substantially more pigment. Oil provides a different (less clear) refractive index than acrylic dispersions, imparting a unique «look and feel» to the resultant paint film. Not all pigments in oil are available in acrylic. Prussian blue has been recently added to the acrylic colors. Acrylic paints, unlike oil, may also be fluorescent.

Due to acrylic’s more flexible nature and more consistent drying time between colors, the painter does not have to follow the «fat over lean» rule of oil painting, where more medium must be applied to each layer to avoid cracking. While canvas needs to be properly sized and primed before painting with oil (otherwise it will eventually rot the canvas), acrylic can be safely applied to raw canvas. The rapid drying of the paint tends to discourage the blending of color and use of wet-in-wet technique as in oil painting. While acrylic retarders can slow drying time to several hours, it remains a relatively fast-drying medium, and the addition of too much acrylic retarder can prevent the paint from ever drying properly.

Although the permanency of acrylics is sometimes debated by conservators, they appear more stable than oil paints. Oil paints fade in color and develop a yellow tint over time; they also begin to crack with age. Acrylic paints have only been in use for approximately fifty years; within that time they have yet alter in ways seen in oil paints. The changes observed in works done in oil are caused by the paint’s binder (linseed oil). Linseed oil dries as an inelastic film. As temperatures rise and fall, this film cracks. Meanwhile, acrylic paint is very elastic, which prevents cracking from occurring. Acrylic paint’s binder is acrylic polymer emulsion; as this binder dries the paint remains flexible.

Another difference between oil and acrylic paints is the versatility offered by acrylic paints – acrylic is very useful in mixed media, allowing use of pastel (oil & chalk), charcoal, pen, etc. on top of the dried acrylic painted surface. Mixing other bodies into the acrylic is possible – sand, rice, even pasta may be incorporated in the artwork. Mixing artist or student quality acrylic paint with household acrylic emulsions is possible, allowing the use of pre-mixed tints straight from the tube or tin, so presenting the painter with a vast color range at his or her disposal. This versatility is also illustrated in the wide variety of additional artistic uses that acrylics afford the artist. Specialist acrylics have been manufactured and used for lino block printing (acrylic block printing ink produced by Derivan since the early 1980s), face painting, airbrushing, water color techniques, and fabric screen printing.

 From: Wikipedia®

 

Deja un comentario

Este sitio usa Akismet para reducir el spam. Aprende cómo se procesan los datos de tus comentarios.

A %d blogueros les gusta esto: