Did you get that speak I mean speck in NJ?
If using chalkboard paint...should you "scuff" up the surface?
And, does it matter if it is wood, aluminum (sluice box blank) or ABS? (which I can't find...)
The gasket material is too hard and slick, for $12 you can get a self-repairing cutting mat from a hobby shop. I have made a few now and they work excellent