2-part epoxy resin. High solids, solvent-free, transparent, glossy.
You can create at least 3mm-thick coats, similar to 50 coats of a traditional varnish, and you can also include objects in it.
Apply it by pouring it onto any non-absorbing or insulated surface.
Coverage on non-absorbing or primed surfaces approx. 1m²/L at 1mm thick.