Making Your Own Paint
Opaque and Transparent Colors
There are two advantages to using dry pigments. One is that storing them in dry form preserves them for a very long time. The other is that they can be used with any binder allowing you more freedom to experiment or try your hand at a different mediums. The only disadvantage is that, if you are a plein air painter you must premix your paints to avoid being confined to your studio. However most artists will agree that, although it appears costly the true advantage of using dry pigments is when grinding paint a little goes a long way.
The first consideration taken when choosing colors for use in your paint is to acquire clarity regarding what constitutes the difference between a pigment and colorant.
Powdered mineral pigments such as Umber and Titanium White when mixed with a medium will produce an opaque color. These are insoluble materials (meaning they will not mix with water) and they retain a constant chemical behavior. These are usually the opaque dull earth colors that cover well and because they are produced from minerals often possess the highest lightfast rating.
Most colorants come from vegetable dye sources or are made synthetically by chemical processing and are generally produced as transparent colors. Many colorants because they are manufactured from vegetation contain carbon, hydrogen, oxygen, nitrogen, and sulfur and are sensitive to atmospheric conditions which is why few are considered permanent or lightfast. Transparent pigments are best used for glazing techniques.
Correct Colors to Use
Understanding the burden of creating truly archival craftsmanship and how it influences the liability of the artist, determining what colors to use to assure life expectancy of a work of art becomes an important issue. The permanence or resistance to fade from exposure to light, know as “lightfastness” of a color relies on the chemical composition of the pigment used.
The American Society for Testing and Materials (ASTM) has developed technical standards for painting materials through documented and continuously reviewed analytical test methods. The method that rates a pigment light fastness on a scale of ASTM I to ASTM V is based on the ASTM D4303 – 06 Standard Test Methods for Light fastness of Colorants Used in Artists’ Materials.
Stringent lightfastness ratings for professional artists paints are:
ASTM I — Excellent
ASTM II — Very Good
ASTM III — Insufficiently for use with artists’ paints
Because the rating performance changes based on the binders used other ASTM artists’ material standards are:
ASTM D 4302, Standard Specification for Oil, Resin-Oil, and Alkyd Paints
ASTM D 5098 Standard Specification for Acrylic Dispersion Paints
ASTM D 5067 Standard Specification for Watercolor Paints
ASTM D 5724, Standard Specification for Artists’ Gouache Paints
ASTM D 6901, Standard Specification for Artists’ Colored Pencils
Most student grade paints are developed with with the users safety in mind where as professional pigments place emphasis on permanence. For these reasons, once you have learned how to handle them safely you should refrain from use of pigments that do not have an ASTM Lightfastness rating of I or II . Shop for pigment and paint companies who openly provide detailed technical specifications about their products such as examples of the list below:
- Guerra Dry Pigments and Pigment Color Chart
- Da Vinci Artists’ Oil Colors and Technical Information Chart
Note: Although some professional pigments will be considered hazardous they will be marked with a CL which notes that it contains toxic elements that can be used safely or CL65 as a warning that it contains chemicals that have been shown to cause cancer, birth defects, or other reproductive harm. Practicing to protect yourself from exposure by inhalation or skin absorption by always being aware of dry powder pigments and their hazards , keeping a clean studio, and wearing (rubber or latex gloves with a face dust mask) is usually all that should be required.