Description: The back is a 4′x6′ piece of plywood, padded with 1″ thick foam and covered with batting. My indoor/outdoor canvas fabric measured 55in wide, which would have been fine if I wanted to run the pattern horizontally. Since I wanted to run the pattern vertically, I needed to cut 2 pieces of fabric to 4 1/2 feet long and sew them together at the selvages, being sure to match up the pattern. I made sure the seam ran down the center of the board.
As for the seating, I stumbled across similar projects on Pinterest that used a piece of MDF board. Genius! I didn’t screw the MDF into the Expedit because, again, I wanted to preserve the bookcase. But, if you have kids I recommend securing it. I also decided against legs so it’s sturdier by being directly on the floor.