Friday, July 19, 2013

Artist Resources: Paint Types

Artists paint is a multi-part system made up of pigment, binder, solvent and additives. In some instances, this is a simple mixture with few ingredients and with other paints, it is incredibly more complicated with many ingredients. Many paints also have fillers to add bulk and reduce the pigment load thus reducing cost and sometimes quality.  Many different additives may be used to encourage specific working properties or performance attributes of the paint.  Each type of paint, manufactured by many companies all over the world, will  have features that differentiate it from one brand to the next.  Although it is usually safe to mix brands of the same types of paints when painting, sometimes it isn't recommended depending on the application or technique.

Most paints are colored with pigments, but not all pigments are created equal.  Pigments range in chemistry, particle size, transparency, lightfastness and stability, therefore each type of paint has to be formulated to suit the unique properties of a pigment in order to be compatible with other paints of that medium and remain stable.  
Each type of paint is different enough to require different needs from a brush.  Some mediums can benefit from the same brush however. An example is that often a watercolor brush will work quite well for egg tempera or casein. However, an artist's application and technique with a medium will alter what brush works best for their style.

Acrylic paint is one of the more complicated paints to manufacture.  It is created with pigment and a water-bourne acrylic binder (water-bourne is the technical term for what we more often refer to as “water based”) (Most often acrylics remain the same hue going from wet to dry, unlike other paints this is not true). Acrylics offer more options than any other paint medium with a great variety of additives, extenders and mediums that the artist can use to alter the attributes of the paint. Acrylics also allow the greatest range of applications from very thick impastos to very watery washes and stains on just about any substrate.  Acrylics might just be the only paint that works well with both natural bristle brushes like Inteboro and with synthetics, like Interlock Bronze.  However, since acrylics range in their viscosity from fluid to heavy body, it is up to the artist to choose what works best.


Oil paint 
in its purest form is simply pigment with linseed oil. Many modern oils include additives like dryers, resins and waxes.  Oil paints tend to have a smooth, buttery working consistency and they take a long time to dry, giving an artist long working time with blending or painting in the studio or outside, (in plein air).  Linseed oil can be used to make glazes with the oil paints to paint in transparent layers.  Solvents, like mineral spirits or turpentine must be used to clean brushes.  Oil painters usually prefer to work with natural bristle brushes for laying in color or working impasto (wet in wet), however, small, very soft Mongolian sable brushes work quite well for blending.  

Water miscible (soluble) oils are a newer paint to the market.  Although they are also made with pigment and linseed oil or alkyd binder, they can be thinned with water and cleaned up with water.  Different brands of water miscible oils vary greatly in formulation, so be cautious when combining brands. 

Watercolor is generally made with pigment and gum arabic. Some water colors include dyes as colorants which may be less lightfast than pure pigmented colors.  Fine watercolor is translucent, each pigment chosen is picked for its ability to transmit brilliant color, yet remain transparent when dry.    Watercolorists use brushes that hold a lot of fluid when painting, like the Faux Squirrel series.  


Gouache is similar to watercolor in chemistry, but the pigments are opaque.  Some gouache also include a secondary binder such as an acrylic. Gouache has been most often used in commercial art and illustration for its brilliance.  Some brands also add chalk and other fillers to the formula to reduce cost, and this will affect the product's look and feel.  Gouache that have no secondary binders are reworkable on the painting surface while wet and when just dry to the touch.

Alkyd is most similar to oil paint in working properties and chemistry, however, it dries much faster than traditional oil paints.  Some alkyds also dry with a matte finish. They generally clean up with mineral spirits much like oil paints.

Casein is made with pigment and milk protein and dries to a durable matte finish.  Like gouache, casein is re-workable on the surface, and great for illustration.  Casein is also compatible with oils, acrylics and shellac for under paintings and use on furniture. Casien tends to remain brittle so use caution on flexible substrates such as paper or canvas.

Egg Tempera uses egg protein to bind the pigment to the substrate.  It is one of the oldest known paints still in common use today, because of its permanency and brilliance.  Egg tempera is not found in tubes in the art store, but rather, artists make it in their studios daily before use with egg yolk and pigment.  

Ink can come in several forms; there are acrylic, alcohol and shellac based inks.  The color in some inks are often soluble dyes, rather than pigments, and therefore not as permanent or lightfast.  Acrylic inks are more often pigmented and waterborne, a safer choice for long lasting fine art.  Alcohol inks are pigments in alcohol and quite versatile with other mediums.  


Encaustic is composed of pigment, damar resin and beeswax.  It is painted on while warm and cools to a soft glossy, yet durable finish.  It can be reworked by reheating the surface at any time.  Easily buffed to a shine, encaustic does not need to be varnished, and it is compatible with many other mediums.  

To learn more about each type of paint, it is best to read the material and MSDS sheets on the manufacturer's website of the brand you are using.   The brands linked in this post have some excellent resources on their websites, but they are not the only brands manufacturing these types of paints.  Look around for the varieties of paints available.  

This is just the wet paint media.  Pastels, both soft and oil are also painting media.  We'll talk about those in upcoming posts.  

Keep Painting
Karyn

For more brush information, check out the Dynasty Brush website.