Here is the information you’ll find on your paint tubes. This is a lot of information which is very important for an artist to know. Let’s go over what these things are and what they mean.
On Golden’s paint tubes, the first thing you see is the color swatch. This shows the color and the opacity/translucency of the paint within the tube. My other professional paints also have color swatches on them but not which accurately show the opacity of the paint. Opacity will also be indicated by a rating. For example: Opacity, Medium.
You’ll find the name given the paint by the manufacturer. This can be anything the company chooses and is often misleading. For example, Ivory black is no longer made with the ivory tusks from animals, yet the name remains. Indian yellow is claimed to have been originally manufactured in rural India from the urine of cattle fed only on mango leaves and limited water, which caused the animals to become dehydrated. It has since been debated whether this is true or not, yet the name remains.
This is why it’s important to understand the color index name on the tube. This is code which tells you what pigment is used in the paint. Single pigment paints are best for mixing colors, as they are pure pigment and binder (or vehicle). Paints which have more than one pigment can cause “muddy” colors when mixing. Let’s look at the color index name on a tube of paint.
The letter P stands for pigment.
Next you’ll see a letter R, O, Y, G, B/Bl, V, Br, W, Bk, which stand for red, orange, yellow, green, blue, violet, brown, white and black. The more of these on a tube of paint the more colors used to make the paint within the tube. For example: Matisse Southern Ocean Blue pigments are Pg7 and PBl15.3 which equals phthalo turquoise in Matisse colors. (This, by the way, is one of the most beautiful colors I have in my work room. I adore this color and have vowed never to run out of it.) The number which follows indicates the specific hue/color of the pigment.
The series number tells you how expensive the paint is. The lower the number the less expensive the paint is to produce. For example, Burnt Sienna is a series 1 color as is Yellow Ochre. Cadmium Yellow Light and Medium are a series 4, while Primary Yellow is a Series 2. Cadmium Orange HUE is a series 2, while Quinacridone Burnt Orange is a series 3. Cadmium Red Medium is a Series 4 while Alizarin Crimson HUE is a series 2. Quinacridone/Nickel Azo Gold is a Series 7. Here is an example from one of my paints:
PY83 PR101 PY42 this stands for Pigment Yellow 83, Pigment Red 101 and Pigment Yellow 42. This color is a series 3, is lightfast, and has an acrylic polymer emulsion vehicle. The name of this color is Matisse Derivan Australian Sienna-another of my must have colors in my work room.
Pigments are the particles in paint revealing color. Every pigment is classified into two basic categories based on chemical composition – Organic pigments and Inorganic pigments. Organic pigments are formed from complex carbon chemistry and are synthetically derived in laboratories. Most organic pigments offer high chroma, high tinting strength and exceptional transparency. When you mix organic pigments, you maintain excellent clarity of color.  Inorganic pigments are not based on carbon chemistry, but instead are derived from natural minerals or ores. Most inorganic pigments offer relatively low chroma, low tinting strength and a moderate to high degree of opacity. (From Golden’s website)
When a paint is labeled as a HUE, it is not made of the more expensive-and usually more toxic-pigments. Hue is usually an indication of non-toxic paints and pigments, safe for kids to use with reasonable precautions. Hues are less expensive paints. If you’re going to be using a certain color as an under painting, for example, you would be better to use the less expensive hue for this purpose. There are many, many artists who only use hues of the expensive paint colors. Some because of cost, others feel hues are safer to work with, and still others because it’s all they can get in their corner of the world. No matter the reason, the quality of hues has greatly improved over the years and they offer stunning color options at a reasonable price.
Lightfastness is vitally important to an artist. This is also found on your paint tube. Most paints available are in levels of 1, 2 and 3. Whether #1 for the most lightfast or #3 is the most lightfast depends upon the manufacturer. Some use stars as their symbol, some use the letter A, some use slashes, some the actual numbers. It’s up to the consumer to figure out what the lightfastness rating of that particular tube of paint based upon the company’s labeling system.
Finally, you will find a product code on your paint tube. Use this when communicating with the paint manufacturer. It can them when the paint was made, where it was made, where it was shipped from, all sorts of neat stuff like that.
Finally, all American made paints should indicate they are compliant with ASTM standards. Not all paints made in other countries necessarily have this on their paints, but those produced in America should.