7 essential information for an artist

In an artist's supply store, a multitude of paint colors can be found. It looks very nice, but among the different qualities and the different packaging, you can be lost and have trouble finding your way around. Here are 7 things you absolutely need to know when choosing your paint colors. 

1 - Fine or extra fine Paint Quality

Paint color is a combination of pigment and binder. The pigment is a colored powder, which precisely gives the color to the painting. The amount of pigment used varies depending on the type of paint. The binder, depending on the technique, can be oil, acrylic or gum arabic when it comes to gouache or watercolor. 

Extra fine or « artist quality » paints require a larger amount of pigment. The pigment concentration is twice as high as for fine « student grade » paints. The extra fine ones are also made with better quality pigments, and the pigment and binder mixture will be ground more finely. 

The interest of this technique is that if you mix the same amount of paint with white, you will keep the coloring power longer. With an extra fine paint you will retain the tinting strength, in other words the intensity of the color longer than with a fine paint. In effecto you will need to use less paint if you are using extra fine colors.

In general, you will notice that fine paints are less expensive and they are packaged in larger tubes. Extra fine paints are more expensive, and they are packaged in smaller tubes. 

2 - The series. 

The series is only related to extra fine paint colors, because they have a very high pigment concentration. They contain up to twice as much pigment as fine paints. Pigments have several origins and they are not the same price. The price of the pigment used to make the color impacts the price of the tube. This is why there are series, which correspond to different price levels. 

Colors made with less expensive pigments are classified as series 1, colors made with the most expensive pigments are classified under higher series. So for the same size tube, a series 1 could cost 5€ and a series 6 could cost 35€. Very often, in a range of paint colors, more than half of the colors are in series 1. This notion of series only applies to extra fine paints. Why ? Because the amount of pigment contained in fine paint is not high enough to affect the price.

3 - The Colour Index. 

It can be found normally on the back of the tubes and is a code composed of letters and numbers. It starts with 2 letters such as PR (Pigment Red), PB (Pigment blue), PY (Pigment Yellow) …followed by a number… based on an international code created in 1925 and used by all color manufacturers. Each pigment has its own Colour Index. It is very important to pay attention to this index, it gives the artist a lot of information. It provides the exact pigment composition of your color. 

If only one code is used, you are dealing with a mono-pigmented color, which is better for mixtures. They are preferred for blending to avoid multiplying the number of pigments in the color. Indeed, if you mix two colors which are each composed of 3 pigments, it is 6 pigments that you will apply on your canvas. And the more pigments there are, the duller the color becomes.  

 If there are several codes listed, you should know that the first pigment is the one that is in greater quantity. They are noted from highest to lowest quantities.  

The Color Indexes are also important because the names of the colors do not always reflect their composition. For example a phthalo blue is indeed made with phthalocyanine blue pigment however manufacturers have not used mummy in mummy brown for a very long time, nor do they, nowadays, disgorge various plants in pigs’ bladders to make sap green. Knowing how to read the Color Index will tell you exactly the pigments that make up your colors. 

4 - The lightfastness.

Lightfastness is the ability of your color to stand the test of time, to resist to fading when exposed to ultraviolet rays. This characteristic is also called “permanence”. To check the level of resistance, there are two indications on the label: the stars and the small bars. The stars are indicated by the manufacturers, and the small bars are actually Roman numerals. This is a classification issued by an American organization called ASTM (American Society of Testing and Materials). It classifies pigments from I to V in Roman numerals.  

It is recommended to rely on the Roman numerals rather than the stars. I: excellent lightfastness, II: very good, III: medium, IV: weak, V: very weak.
So, contrary to what one might think, the higher the number, the lower the resistance.. Therefore, colors with a lightfastness I or II should be preferred. 

5 - The opacity. 

The artist has to know that it is the pigment that gives the color its opacity, that is to say its covering power. Some pigments are less opaque, they are even said to be transparent. The pigments can therefore be opaque, semi-transparent or transparent. Transparent pigments are preferred for glazing, opaque pigments are preferred by painters who paint "alla prima" as did the impressionists for example. 

There are two codifications that allow you to know if you have in your hands a transparent or an opaque color. Letters: O, opaque; O/T semi transparent, T transparent Small squares:a black square indicates an opaque color, , a black-and-white square, a semi-transparent color, and a clear square , a transparent color. 

6 - Imitations, tones and substitutes. 

Sometimes, if you are not careful, two colors can look similar but with very different prices. For example, looking at the picture of the cobalt blue tubes, you can see that they have the same shade, but in the shop, one is more expensive than the other. The two colors are not produced with the same pigments. The one on the left is a real cobalt blue when the one on the right is an imitation made with a combination of several synthetic pigments. 

These imitations are sometimes called "substitute" or "tone", which means the same thing: you are not dealing with the real pigment. The only thing they have in common is - the same shade. One is made from a single pigment, while the other is a combination of several pigments. 

The result, especially when mixed with other colors, will be very different. By reading the indications on the back of the tube, we can see that they do not have the same series. Real pigment are more expensive, and they do not have the same Colour Index, as they are made with different pigments. The true color is mono-pigmented while the imitation is composed of 3 pigments. They don’t have the same opacity either, in our example the real cobalt blue is a semi-transparent pigment, while the imitation is opaque thanks to the white pigment that has been added.

7 - The batch number. 

Where the tube is folded, you can find small characters engraved. They correspond to the batch number. It’s the number that should be given to the manufacturer if you have a problem with the quality of the paint in the tube. This number will be useful to identify the date of manufacture.

Thanks to this article, you now have all the necessary information to choose your products in store.