The Materials (Part 1)
When you open a catalog or enter a fine arts supply store, you can only feel overwhelmed by the abundance! How can you not make a mistake? The only solution: a little equipment, but good equipment!
Tubes or Pans
Pans: limited uses
They are most frequently used by botanists or for travel sketchbooks, or even for illustration. Half-pans are too small for many types of brushes. Used too dry, they damage fragile brush tufts. On the other hand, economically, it is not a good bet. Conversely, a 5 ml tube contains the equivalent of two half-pans. Finally, too often, "ready-made" boxes are not of good quality or do not offer a very practical color palette.
Watercolor in tubes: the best choice
One of the most represented brands is Winsor & Newton® (WN). Let us also mention Lefranc Bourgeois®, Rembrandt® or Sennelier®, Daler Rowney®, Daniel Smith®, Mijello®, Lukas® or Schmincke®, etc. There are tubes containing up to 37 ml.
You can start with just three 5 ml tubes: one blue, one red, one yellow. For example, you will need the equivalent of a cobalt blue 178, a magenta 545, and a winsor yellow 730 from Winsor & Newton®.
Category 1 is the cheapest. Cobalt blue is a 4, magenta is a 3, yellow is a 1. You will find other information on the label of each tube, including the name of the pigment(s) composing the color, their lightfastness, as well as their degree of transparency.
Making your own watercolor?
No special aptitude for playing little chemist is necessary!
Gum arabic
It comes from the acacia tree. Often present without our knowledge in processed foods, gum arabic is used to amalgamate other products. It is the binder. Without it, the pigments would not remain agglomerated in the fibers of the paper. Each manufacturer adds or doesn't add its own special little ingredient (for example, glycerin or honey) which makes the difference from one brand to another.
Solid or liquid?
It can be found in solid or liquid form in organic or fine arts stores. I advise you to start, if you really want to make your own colors, by using the liquid form instead. The solid form needs to be dissolved, it is better to do it 24 hours in advance. Cold it takes longer, in a bain-marie, it's faster.
Once liquid, the gum arabic is gently added to the pigment in a mortar or on a specially designed thick glass plate; failing that, a ceramic tile will do. Avoid lumps! Some pigments are quite expensive, only make the colors you need in large quantities, for example primary colors. Made this way, the watercolor paste must be used quickly, otherwise it can ferment (note: Sennelier® offers a preservative).
You will find many other watercolor recipes on the web. You will keep it in a closed palette, sheltered from dust, or cat hair!