Want to paint shower base... I think it is fiberglass.

Recommend paint type please ( or link )

Epoxy pool paint is best. Preparation is critical. Remember, fiberglass flexes so you might find some cracking. Search "painting a fiberglass pool".

Thank you for the reply.

I would think this was a custom built shower pan, as it's an odd size, 36" x 30".
Could you please take a look at image... can you tell if it is fiberglass ?

Looks like fiberglass but doesn't look like it is part of the original pan. What is the caulk for?

Thanks for the reply.

We purchased the house, do not know who built shower.
I would think that is part of the base finish, that they let wrap up the onto the flange.

I've never seen a similar layout. When I do a fiberglass pan/shower, rarely, I would bring the shower backing, Duroc or similar down to within 1/8-3/16" of the base. Nominally you would be about 1-2" off the floor. Use thinset to fill all the voids and corners. Then you can tile, leaving another gap, similar to what you have. I usually grout everything except the bottom gap. I finish with a good silicone caulk, base gap and wall corners. Was there any wall covering? The last one I did had a preformed base with a 1" flange. Purple board on the walls, screwed the base to the wall studs, tiled as above.