Unfortunately I had to go the acrylic route AND with needing a larger palette, I came up with this; it's a cake/cupcake container from WM for just $10!!! I used a quadruple layer of the blue shop towels on the bottom, wet to hold moisture. Then parchment paper on top as the palette. The cupcake container can hold your thickened acrylics with a posterboard 'cover' (or you can wrap with cling wrap). And I used cheap foam insulation under the lid to seal it. CHEAP!!!!!