Great set of 4 amber and 4 red tumblers. Heavy glass Sommerso clear bottom over a deep amber or a dense red.
Amelio Cenedese here made tumblers borrowing Carlo Scarpa velati technique. These is made with a thin wheel grinding over the surface. It’s not a battuto where the little strokes on the large wheel give the effect of forged iron (ferro battuto). Here is more like wood grain. It’s chiselled line by line.
Cenedese mastered the Sommerso technique through the works of Dal Ros. Inciso is a perfect cold finish for Sommerso, see pictures.

A great set, unique and precious for the use of these techniques which are unusual on a glassware set.
For the summer, where light enhances the beauty of the finishes and of the Sommerso.

I am assigning these to the 1980s where there was a moment of popularity of expensive colored tumblers.