How do I know if I need Deep Pour or Bar & Table Top Epoxy?

Go by the total depth of epoxy you want to end up with.

Under 1/4": UltraClear Bar & Table Top Epoxy. It self-levels to 1/8" per flood coat, and a single 1/8" flood coat is the standard finish for bar tops, tables, and countertops. UltraClear Deep Pour Epoxy cannot cure this thin.

Exactly 1/4": still Bar & Table Top Epoxy. Pour two 1/8" flood coats 4 to 6 hours apart.

1/4" to 1.5": either product works. Bar & Table Top Epoxy can be built up in 1/8" layers every 4 to 6 hours to a maximum of 1.5". Deep Pour Epoxy fills the same depth in one pour (up to 1" per layer), so from about 1/2" up we usually recommend it. The trade-off is an extra step: Deep Pour has to be sealed under and top-coated over with Bar & Table Top Epoxy.

Over 1.5": river channels, molds, and thick castings with embedded objects need Deep Pour Epoxy, poured 1" at a time every 12 to 24 hours up to 6" total, with Bar & Table Top Epoxy as the seal coat and the final top coat.

Whatever the depth, the surface people will actually use should be Bar & Table Top Epoxy. It is the harder, more scratch-resistant product. Deep Pour is for depth, not for the finish.