The vacuum box
This is a simple box sized to fit the intended use. In this case it was made to fit the biggest frame that would fit in my oven. It uses 12" x 16" plastic "blanks" which work out evenly for a 4' x 8' sheet. The inside joints are caulked to make them airtight and a hole cut to fit the vacuum source; here a built in household vacuum. Some tape made the seal to the box. The top is a piece of melamine shelving board drilled with 1/4' holes in a grid. The ledge isn't necessary. I just copied someone else. It has some foam tape on it for sealing.