My mother did some sewing when I was younger. She went to a fabric store to buy supplies. I came a cross a roll of hex plastic sheet. It was a slightly larger hex than the original blue max but close in size. It was around 2ft wide(63cm) and you could buy it upto 6 ft(196cm) long.I used to roll it out and use it for whatever game we were playing and just roll it up at the end of the day. Being plastic, we could write on it with the china markers and erase it when done too. So maybe you could check there. We had a place called JoAnne Fabrics.