If you are purchasing a PDF document or intend to make your own visual symbols then we cannot recommended using VELCRO® Brand hook and loop enough.
VELCRO® is available by the metre from Create Visual Aids and you can choose between buying hook (the rough side), loop (the soft side) or hook and loop coins. The VELCRO® has adhesive backing and the strips are 20mm wide, whereas the coins are 22mm in diameter. All of our VELCRO® is white.
As a general rule, at Create Visual Aids we use soft loop on the back of all symbols, and rough hook on the boards.