The Art Store seems to be the place to go to ask questions about art materials and their uses. This FAQ was built to answer some of your most basic questions. More technical questions should be emailed to us here.
Q: What is all paint made of?
A: A binder and a colorant. The difference is the type of binder that is used to carry the pigments and dyes for the colorant. A binder is the substance that the pigment or dye is mixed into to create paint. A binder is also known as the medium or vehicle. Sometimes a manufacturer will add filler to a paint that diminishes the binder strength and/or the paint’s pigment concentration. This is usually referred to as “student grade”
Binders can also be natural or synthetic. Natural binders include linseed oil and gum arabic. One synthetic binder is acrylic polymer emulsion, which is used to make acrylic paint. Pigments or dyes are mixed with a binder to create a workable paint that will adhere to a support, or substrate, like a canvas or wood surface. As the binder loses moisture into the air through evaporation, it becomes more rigid and stabilizes the pigment onto the support surface.
Q: What are the differences in the paint types?
A: The difference is the type of binder that is used to carry the pigments and dyes. A binder is the substance that the pigment or dye is mixed into to create paint. A binder is also known as the medium or vehicle.
Binders can also be natural or synthetic. Natural binders include linseed oil and gum arabic. One synthetic binder is acrylic polymer emulsion, which is used to make acrylic paint. Pigments or dyes are mixed with a binder to create a workable paint that will adhere to a support, or substrate, like a canvas or wood surface. As the binder loses moisture into the air through eva poration, it becomes more rigid and stabilizes the pigment onto the support surface.
Q: Why are some colors more expensive than others?
A: The price of artist paint is determined by the quality and the amount of the pigments and dyes that are used in it and the quality of the binder. It is much more expensive to extract natural pigments and dyes than it is to manufacture synthetic colors. This makes a tube of paint that is made with a natural color more expensive than a tube of paint made with synthetic color. For example, cadmium red is made with cadmium, a transition metal on the periodic table (Cd, Atomic Number 48), and is much more expensive than cadmium red hue, which is a mixture of synthetic colors. Artist quality paint has a high pigment load. This is the amount of pigment and dye that a manufacturer mixes into the binder. That means that there is more color in your paint. Artist quality paint is made with high quality binders that will dry evenly, stay flexible, and adhere to the primed canvas very well.
Q: How toxic are art materials?
A: Most are not toxic to a healthy immune system. Some are toxic to even a healthy immune system. You should always research the art materials you are working with to make sure you have set-up your studio properly for your and others’ health concerns.
A lot of you have been asking how to set up a healthier studio at home. We hear you!
For the next few months, we will focus on different aspects of home studio safety in this special section of the newsletter.
Q: What is the difference between a pigment and a dye?
A: There are two different types of pigments: Natural and Synthetic. Pigments are insoluble materials that are ground into a fine powder so that they can be suspended in the binder. Insolubility means that pigments can never be dissovled into the binder, the fine particles of the powder are suspended and stay solid in the binder. The binder surrounds the pigment particles and holds them in place.
Pigments produce paints that are more opaque than dyes and have low tinting strength. Opacity is the ability for paint to cover and hide another dried color that it has been applied over. Tinting strength is how well a color mixes with other colors. (Example: When mixing blue with white, how well does the blue disperse into the white? or How blue does the white look after the mixing?)
The first colorants that were used to create paint were naturally occuring earthen pigments. Prehistoric people used ochres and iron oxides to create images on cave walls in Lascaux, France. Many natural insoluble pigments are still used today in artists’ paints. Metals are also natural insoluble pigments, like cadmium, titanium, and lead (very toxic).
Q: How are paints rated for being lightfast?
A: Lightfastness is how well a paint resists fading due to ultraviolet exposure. Lightfastness is measured considering how much ultraviolet light a paint is exposed to and for how long. Because the pigments or dyes are the color of paint, lightfastness is a property of the pigments or dyes that are used in a paint.
Q: Why use Artist’s Grade paints?
A: Whenever you can afford to. The paints are easier to mix to the colors you may need. They are also much more vibrant and will last for a longer length of time. They also have a much higher standard of control in all aspects of manufacturing.
Q: When are “student grade” paints acceptable to be used?
A: Acrylic student grade paints are very good for younger students. The flowing consistency of student grade paints enables elementary students to use these very easily right out of the tube. There is no need to mix any acrylic mediums into the paint.
Adults might consider using student grade paints for making paintings that are not intended to be lasting works of art: color experiments, sketch paintings that will be copied into larger works, paintings you will not want to keep for a long time. The lightfastness of student grade paint is not formulated to create lasting works. Please note that while these are called student grade paints, most university professors will not allow their students to use them for class assignments.
Q: What is gesso?
A: Gesso is an absorbant ground that is used as a primer to prepare surfaces for many different paints. Most gessos consist of a binder (oil or acrylic), calcium carbonate (marble dust) and a colorant (usually titanium white). The binder is what prepares many surfaces for being suitable for painting on. If you wish to make your art more archival, you will need to apply PVA to the substrate before gessoing. This is very important when oil painting. If not used there is a very high chance of your painting deteoriating over time due to spoilage from the oil rotting the canvas from the front to the back of the painted surface.