The defining characteristic is whether the transfer is designed to be permanently fused into a glass or ceramic substrate through high-temperature firing (vitrifiable) or whether it adheres to a surface through pressure, heat, or adhesive without kiln firing (non-vitrifiable). Vitrifiable decals contain glass-based pigments that bond chemically with the substrate during firing; non-vitrifiable transfers use conventional inks or adhesives. The intended application method and substrate type are the operative classification criteria.

Yes. When vitrifiable decals are applied to ceramic or glass articles intended for food contact — such as mugs, plates, or bowls — the finished article must comply with FDA regulations on lead and cadmium leaching from ceramic foodware. While the decal itself is classified under 490810 as a component, importers of finished decorated ceramics should ensure their suppliers' decal formulations meet FDA leachability standards and retain test documentation to support compliance.