I think it's probably acrylic polymer paint. I'd say you could give the peeling area a light sanding and paint it over with some white acrylic polymer paint as a short-term fix. I'm guessing that you might want to give the whole thing a light sand and repaint if you want something longer-term....short of ripping it all out and replacing it, of course.

This looks very similar to the bathtub I just had refinished in my home. In my case, I was the one who did the cover up job. I used the “tough as tile” refinishing kit. They likely uses something similar. It turns out to be much less tough than tile, and my cover up job was peeling after two years of heavy use. No idea how long it’s supposed to last but for the amount of work it took, I was disappointed. Refinishing a bath tub is very hard to do by yourself. It’s possible you could patch this spot with a “tough as tile” product but I would not recommend that. I paid a refinishing company to come out and redo my tub last week. It looks amazing and it comes with a 10 year warranty.

Yeah, I may go the route of hiring a company. So, do they peel off the old stuff and retreat the whole thing? You hire a specialist in tile refinishing? How is the durability? Trying to weigh refinishing versus new tile, but I’m guessing we’d have to take out the tub if we did retile

They strip the old finish, then sand and treat the entire surface so it’s ready to accept the new finish. Similar process to using “tough as tile”—only I sanded/cleaned/treated the entire thing by hand and it me took days, they had power tools and were done in a few hours. For mine they used synthetic porcelain resin, there are probably other finish options. Can’t speak to the durability yet as it’s only been done for a week, but it looks brand new and feels higher quality than the tough as tile finish. You cannot use certain harsh cleaning products on the new finish, they gave me cleaning and care instructions. I did not want any of my tile touched, it’s vintage and wraps around the entire room. It would’ve been an entire bathroom renovation. So I went for this option. $774

Edit: it was done by a tub and tile company

Yep, this seems like the way to go. I’ll price out some options. Was that just for the tub or for the tile as well?

That was just for the tub

Ya I hired a top rated company on HomeStars to refinish my tub. He oversprayed one part and there was a large drip mark down from side of tub from top to bottom of tub about midway along long side of tub. I called and person who answered stated she has seen this from time to time and too much paint applied which yes I agreed because I’ve done spray painting before. Put through to owner and he said it’s because my faucet was dripping. Faucet is at end of tub almost 3 feet away from drip!. I just replaced the valve previously as the single lever handle started getting tough to rotate. It was not leaking and a moot point as its nowhere near the drip. Also we all showered the day before to ensure no residual water would drip the following day when work was to be done. He came to respray and it was terrible. There’s a defined raised rectangular newly painted area measuring about 5 inches wide by 16 inches long to bottom of tub covering where drip was. And the overspray now on tiles and around repair on tub because it was obviously not taped off so now was rough feeling to touch and was not cleaned off tiles and not polished on rest of tub by his “repair”. And within 1 year I began to have pieces chip off and now about 8 years later, I have about 15 areas of chipped paint. Never again. I’ll check how those acrylic tub overlays are like Bath Fitters when I ready.