When I lived in a very small apt., I purchased a couple pieces of paneling (the old fashioned thin stuff used in dens). I cut them to 5' long (the store will do that for you). I kept these under my bed and when I needed a large cutting area, I put them on the bed and then lay my cutting mat on top of them. Not the most ideal, but it worked fine. They gave me a fairly firm underlayer and they stored easily out of site.