Artists upgrade pigment first and paper last, which is precisely the wrong order. Paper decides how the water moves, how long you have to work into a wash, and whether a colour can be lifted after it has dried.
Nothing in a watercolor kit changes the result as completely as the surface underneath it.
Cotton against cellulose
Wood-pulp paper takes a wash and holds it where it lands. Cotton rag lets the water travel, which is what produces soft edges and graded skies without visible effort.
Cotton also survives lifting. Scrub a mistake off cellulose paper and you will destroy the surface; do it on cotton and you will usually recover a workable sheet.
Choosing a tooth
Hot press is smooth, and rewards fine botanical and ink work while punishing hesitant washes, which pool visibly. Cold press has moderate texture and is the sensible default for almost everything. Rough breaks a dry brush stroke into sparkle and suits weather, water and stone.
Most painters need one cold press block and occasional sheets of the other two.
Sizing is the invisible variable
Sizing is the gelatine that stops paper behaving like blotting paper. Too little and colour sinks in dull and immovable; too much and it beads and refuses to settle.
If a sheet feels like it is fighting you, sizing is usually the reason — not your brush and not your paint.
Written by Ines Delacroix