PEVA stands for polyethylene vinyl acetate, while EVA stands for ethylene vinyl alcohol. Both are used for making shower curtains. They differ in how they react to water. PEVA is hydrophobic, meaning it repels water; EVA absorbs water.
If you use PEVA, you won’t see much difference between your old shower curtain liner and your new one. But if you’re replacing an EVA liner, you’ll notice a big change.