I have a question about the paper you use. Do you paint while the paper is still attached to the block? I bought one and thought that the other papers beneath would get ruined by the water.
Yes, definitely. It being attached to the block is what prevents the paper from warping. Just leave it on until the piece is dry, and then remove it. Watercolor paper is fairly thick, so it shouldn’t bleed through to the sheet below. However, if you are doing a very wet technique, the paper underneath might get a little damp. It will return to normal when it dries.
I guess there’s a chance that a really cheap block could get ruined, but even with cheaper paper I haven’t had a problem. I think Canson is the cheapest one I buy.