I use Banana Boat 50 SPF Sunscreen. At first they're resistant, I think because the skin is, at best, irritated and dry because they're so sensitive. At worst it may hurt because it's burnt. My girl will actually blister and peel if she's left without her mask and her skin stays dry and flakey even with the mask without the lotion. Once they figure out that their skin doesn't hurt anymore with the lotion they come around and this filly, the one I call Linda Blair and threaten to call an exorcist for, has actually calmed way down now that lotion is a daily ritual. The boy Skippy, isn't nearly as sensitive but he still likes his lotion.