The gloss finish on Onyx Collection products is a very high grade polyester gel coat. The gel coat is applied to the molds and then the product is cast in afterwords creating a bond that will last forever (also stated in their guarantee). As for the matte finish. It has more of a dull or corian finish that is essentially the same process except the finish is sanded off (product is still sealed). The matte finish (a little more expensive with less color options) will show less water spots but as stated before the maintenance and cleaning of this product (both gloss and matte) is exceptionally easy! Here is a link that might be useful: Onyx shower colors

Interesting, I too am considering one of these cultured marble or onyx vanity tops. But they puzzle me. At my work they redid the ladies rooms a few years ago. One got laminate, others what I believe is cultured granite. I thought it was some sort of shiny corian (or similar) at first, then came across a display in Home Depot made by US Marble that looks identical. The reason I'm considering it is how well it's held up with dozens of people using it every day. It really does look nice. The laminate top on the other hand is totally de-laminating. (Not that I was considering that...just saying) I'm puzzled because it appears to be a plastic impregnated with marble dust and the underside is unfinished. In my old MBR we have what I always called a "cultured marble" vanity/sink top. Mine is almost like china. Like a bathtub. Only beige swirled white 'marble'. It's glazed on both sides. If you open the cabinet you see a smooth porcelain-like sink bottom. Not so with these other cultured marble sinks at work and in HD? They look like foam blown into a mold underneath. Or resin. Have they changed how cultured marble is made over the years? Was it different decades ago? The 2 materials seem totally different. Or did they make total china vanity tops with integrated sinks years ago? Also, my home counter is very cold to the touch. The work/HD counters are warm, like plastic. Any thoughts?

I agree. We have the countertop and its scratched and looks okay. Out shower is matte finish and it looks nice, but the base is hard to keep clean. Their customer service was not hiw i would treat people. Still waiing for Victor to call from 2 years ago to let me know when they are in the area lol Hope you find something that works

I think if I were to put it in as a shower base, I’d go with a matte finish because it would seem like it would disguise film or soap scum that might buildup between cleaning. The bowl of my sink is Onyx White; round and molded in. I have a cultured marble countertop in another bathroom; I think looking at them from the top they seem like similar products. And when I tap them with my nail they both have a nice hard sound to them- neither sound hollow or plastic-like. However, I think my cultured marble has yellowed slightly since I had it installed 9 years ago- but, it could be my imagination or lighting. I specifically sought Onyx for my bathroom because my mother has an Onyx white countertop in her bathroom that looks exactly like it did 21 years ago when it was installed. I wasn’t present during the entire installation, but, I know my contractor installed green drywall in and around the tub/toilet area and adhered the Onyx directly to the drywall. They used a color match seamfill for the corners; it looks tight, and of course, my contractor said I wouldn’t have any leaks- but, I don’t think any options we have would be 100% leakproof!