Typically the foam slabs are 1-1/4 inch thick and the boards are 1/2" to 1" thick. To get about a 3 inch overlap of vinyl around the back of the board to allow adequate stapling you need a piece of vinyl that is about 22-1/2 inches by 58-1/2 inches. The calculation is shown below:
1-1/4 " foam + 1" board + 3" overlap = 5-1/4 inches additional vinyl per side
5-1/4 inches/side X 2 sides = 10-1/2 inches additional vinyl (additional over the board dimensions)
For example, if you had a 12" X 48" board (typical of most bench presses) you would need a piece of vinyl that is (12" + 10-1/2") by (48" + 10-1/2") or 22-1/2" by 58-1/2".
This size (22-1/2" by 58-1/2") can be optimally laid out on our 50 inch wide rolls as seen in the sketch below. Your exact size may vary, but the process will be similar.
Cut the long 5 inch wide left over strip in half lengthwise to form two long strips 2-1/2" wide. Then staple them to the edge of the boards before covering them as described in our upholstery tips section. This helps reduce wear and fretting caused by the edges of the boards.