This is a replica of the grail found by Indy in the third film of the trilogy. The dimensions for the cup come straight from an auction of one of the screen-used grails, si I think it's pretty accurate. After printing on my 3D printer, the cup was smoothed out with auto filler and primed and painted to resemble a warm red ceramic. Real gold leaf was them applied to the inside and outside of the cup. Then everything was weathered back to resemble the rough and humble cup of a carpenter seen in the film.

Holy Grail

Indiana Jones
and the Last Crusade