I like the Art of Venice definition. If sommerso covers one colour cased in clear, then the development and use of the term "sommerso" really doesn't mean much. For example, is Landberg's dusk series for Orrefors properly called sommerso?
What's the opinion on this one, 7.75 cm wide and 9.5cm high? (Sorry for the hijack, Kane; just trying to clarify for myself.)