Have you thought about pool table felt I don't know how wide the rolls are but it does come in many colors

Hello,

If your table and floor is sturdy enough then I suggest you line it with a membrane and use builders sand.

Excellent when dampened for sculpting and no more raised trench systems etc.

Best wishes,

Chris

https://meninboxes.blogspot.com/2012/11/major-general-tremorden-rederrings.html