Best crystal clear acrylic

For encapsulated nail art, what is the best clear acrylic? How do you get that look? Does it need to have gel topcoat to make it like glass?

I have cnd retention + buy havent tried it out yet (nervous newbie)

I also have the opi absolute clear (dumb dumb me never bought the monomer liquid to go with it, so I'm looking for a small bottle to go with it as I have heard it's pretty good.

I'm in Canada and don't have a lot of the brands I often see here