Paper
Cold-press, hot-press, and the weight of good paper.
The weight of good paper
Paper isn't a support, it's a partner. The right weight and tooth will carry water and pigment without buckling or complaining.
What we use
cold-press toothy, for watercolor hot-press smooth, for gouache weight 140–300 lb rag 100% cotton, no acid
Why it matters
Cheap paper fights you. Good paper takes the water, holds the color, and gives it back the way you left it.