What material to use for a backdrop for pool shoots

I was interested in trying to use some fabric for a backdrop in some of my pool shoots with models and i was wondering what material works well, and wont be ruined or run its colors after the first use.

Here is a couple of my latest!

I bought sliding glass door curtains. I think they measured 5'x9' and came in packs of two or three. I had them professionally sown, and then hand glued, weights to them so they would not float or be pushed around by the pool jets. Total cost was around $35.

I never encountered a problem with the fabric loosing color or bleeding. But I was also in a saline pool.

There are a lot of different options you can use. Pool liners and plastic liners, fabrics, plexiglass, all will give you a different look to your image and should be experimented with.