I tend to go to bed with wet hair, and over time, it's terrible for your pillows. I just bought new pillows and wanted to save them from a fate like every other pillow I've ever owned, so I gave these a try. The terry cloth outer surface is fairly soft and it has the added benefit of keeping the pillowcase from sliding off. The inside has a rubberized surface that definitely keeps water out. The only drawback I can see to these covers is that they're a tad snug, so they don't allow much room for your pillows to "squish out" under the weight of your head. On the other hand, if you've got pillows that are losing their loft, this could plump them up a bit.