waterproofing wall in bathroom with no tiles.

[twm.bwen]

Hi there, I've not posted on here in years but diy calls again.
I am redoing our bath room. We want it to be tile free but are going to have a free standing bath which will be against two walls. We will have an oval shower curtain which will prevent most splashes hitting the walls but we would be fools to say we don't need to waterproof the walls.

I am aware of aquapanel and AMD various tanking paints but they all seem as a prep for having tiles put on.
Is anyone aware of a proven smooth finish waterproof board that can be simply painted over? The nearest I can see is MR plasterboard but I'm not sure I trust it.
There are shiny PVC sheets but they make your house look like a hotel. I just want a normal silk paint finish.
Any suggestions?
Thanks

 

[foxhole]

Pvc panels in a matt finish are available.

 

[twm.bwen]

Thanks for your reply, where can I get them?