I use aluminum baking sheets (aka sheet pans) as work surfaces for a lot of our projects. They keep glue off of the table and keep small parts from rolling away, but above all, they make it easy to move the project aside for a few minutes or hours and then bring it back without a lot of disruption. I often wish our art area (dining room) had one of these. I'm pretty sure I'd put warm cookies on mine, too.
You can see the kids using sheet pans for playdough just a few posts ago. Sometimes I have the kids finger paint directly
on the pan instead of on paper, and then just rinse the pan when they're done.
These pans are perfect for oobleck, too. If you've never tried making oobleck, PLEASE do: 2 parts cornstarch +
1 part water = non-toxic, mind-bending Non-Newtonian fluid. Fun if
you're 2 or 20 or 100.
Plain white oobleck is wonderful, but you can have lots of fun with color mixing, too. For mesmerizing color, you can't beat adding little flakes of dry watercolor paint, which dissolve slowly, leaving color trails, but adding drops of liquid tempera or food coloring works, too.
Oobleck is a shear thickening non-Newtonian fluid, which basically means that pressure makes it more solid. If you punch it, it's hard, if you poke it, it's soft. Squeeze it and it breaks, let go of it and it drips.
Here's an amazing video of oobleck on a vibrating surface. I can't wait to try that!