Glass is relatively flexible and tolerates large temperature differences. With my shards, there is also the irregular surface, which initially prevents a view of the inside.
To make the variety of colors visible and to preserve the collages like a snapshot, I use crystal-clear, UV-stabilized epoxy resin. This is dimensionally stable, impact-resistant and can be colored with pigments.
Mixing the components requires the highest level of accuracy and cleanliness. My studio has thus become a laboratory and workshop in one.
Based on my experience with various agents, I only use synthetic, chemical dyes as pigments. This ensures even curing in combination with extremely long color fastness.