I'm hoping to replace some old plasterboard boxing in my bathroom with some type of high gloss white plastic. I was thinking conti board but I heard of some high gloss plastic which might be more suitable, although I can't recall the name. I will build a timber frame and just need to clad it. The boxing is to fill a space behind the toilet and create a usable shelf / surface. Any tips on what would be an appropriate material would be much appreciated. Thanks.