Water Colors Paper
The best permanent paper for watercolors is made from linen and/or cotton rags, which are boiled, shredded, and beaten to separate the fibers; the material then assumes the form of a smooth, flowing pulp The best watercolor papers should not contain bleach. Care must be taken to avoid all contamination by particles of metal The huge paper industry of today, with all its technical refinements, is on a mass-production basis, and even in its most careful manufacture of grades for the finer sort of commercial purposes is a thing apart from the comparatively small-scale industry which produces artists' papers. The most preferred handmade or mold-made papers are "D'Arches" (French) and Fabriano (Italian) are also available.
The material used for sizing the best watercolor papers during their manufacture is a solution of polymer, and the amount and strength of which is of considerable importance to the properties of the paper. Papers sized with hide glues tend to yellow. Paper that has been made with too much sizing will give irregular or spotty results, while that which is too absorbent will give dull, sunken-in effects.
Fine papers are watermarked or embossed with the manufacturer's mark, the side upon which this can be read being the right side. Many papers are well finished only on one side; the wrong side may contain irregular spots, flaws, and blemishes which do not show up until painted upon, or its grain may not be the same. Other papers may be used on both sides equally well.