Watercolor paints are made by grinding powdered pigments and suspending them in a water-soluble binder. The binder is a very complex mixture of many ingredients that can vary based on the pigment being used with it. Originally Gum Arabic was the main ingredient of the binder, but it has been replaced by Kordofan Gum in modern watercolors. The purpose of the other ingredients is to ensure a high-quality product that will provide the longest possible life. Preservatives are added to eliminate bacteria and fungus from forming. Glyciane can be added to make it more flexible. A wetting agent is often added to aid in the flow of the paint. Sometimes starch, dextrin or gum tagacanth is added to thicken the paint. It takes many years to learn the art of grinding and preparing watercolors. It is not recommened that you try to manufacture them at home. Leave it to the skilled craftsmen to produce the highest quality product for you to use.
Pan
Pans are designed for easy transportation and working outdoors. They are made to fit into an enameled-metal or plastic paint box, that holds the colors neatly in place and make them readily available when you need them. They can also be more economical because there are no leaky tubes, so there is minimal waste of excess paint. One drawback to pans is the lighter colors are easily dirtied when mixing and they will often need cleaning.
You might find that new pans of color may stick to the lid of your enameled box. After each use it is a good idea to remove any extra moisture from the pans with a damp sponge. If possible, leave the lid open for an hour or two in a warm place before closing them up and putting them away. This will let any excess moisture evaporate.
Tubes
Tubes do not lend them themselves to working outdoors, rather they are good for larger studio pieces.
