You can use either side. I had the patchwork fat quarters from Fat Quarter Shop - Mill Book 1892. Plus I had the backing Grunge fabric. My camper fabric is brown, tan and beige. This matches good enough because I didn't want to buy any more fabric. The foam was pretty expensive because I had to have 5" deep. I could only find it online. The width was exactly right, but my husband had to cut the rounded corners with a 8" hacksaw. It worked ok. The cushion is nice and stiff to sleep on, now.
Linking up to Finish it up Friday at Crazy Mom Quilts.