A great “upcycle” for styrofoam meat trays is to use them in place of linoleum boards for creating a template for printing.
The one little problem I encountered was that a lot of meat trays are already compromised; they have dimpled or stamped bases, or the glue to hold the absorbent paper in the tray does not come up. So, I had to work around those imperfections to cut out a flat smooth piece of styrofoam.
We used linoleum block printing inks and two brayers- one for inking, one for rolling the paper on the styrofoam template.
This ended up taking a full two hours to complete with a break in-between printing to wash off our styrofoam and brayer to switch colors.