Watercolor blocks

I would like to thank the person or persons who invented watercolor blocks. I normally use Arches watercolor blocks because I like the paper and because it's wonderful not to have to worry about my paper warping. I've been working on a specific painting and I wanted a different size than the watercolor blocks I normally use.

 I still used Arches paper but I didn't tape it down or stretch it, with a smaller painting you can get away with that but apparently my paper was too big because it's been warping.  A reminder to me and everyone else to tape or stretch larger pieces of paper and a reminder of just how nice it is to have watercolor blocks.