Breadcrumb Home FAQ Glossary What does transparent, crystal and Opal mean? __BACK_TO_CATEGORY Query SEARCH Category(4) All categories Installation (2) Product (2) Warranty (2) What does transparent, crystal and Opal mean? • Transparent: one can see the shape, not the colour. • Crystal: one can see the shape and the colour. • Opal: one can’t see the shape or the colour.