The tiles used in the mosaics of antiquity were manufactured from ceramics and glass. During Byzantine times, however, artisans began manufacturing a type of tile called Smalti tiles, which they made by mixing molten glass with various metal oxides. The metal oxides were used to add iridescent colors to the glass, which was then poured into slabs. When the slabs cooled, they were broken up into smaller tiles.
Today, metal mosaics are chiefly used to loan color and style to kitchen backwashes, feature walls and commercial spaces. Metal tiles are typically made from stainless steel, copper, bronze or gold alloys. Most available metal tiles aren't made entirely from metal. Instead, they're made from metal overlays on ceramic bases.
Fiberglass mesh backdrops are frequently used in metal mosaic projects, to make laying the job of laying out the metal tiles easier. Tiles are available either as individual tiles in a variety of sizes, or as sheets of tiles. Both tiles and sheets can be cut and shaped using wet diamond bladed saws. Metal tiles can be mixed and matched with ceramic and glass tiles to create striking visual displays.
When working with metal tiles, it's important not to scratch the metal finish. Experts recommend using unsanded grout only in the tile joints.
After the tiles are installed, their surfaces should be protected with a sealant. Stainless steel tiles are the only metal mosaic tiles that don't need to be treated in this fashion since stainless steel doesn't oxidize or scratch.
Commercial sealants are available that are specifically manufactured for use with metal tiles. Without a proper sealant, metal tiles installed in kitchens or other places where moisture may accrue are likely to tarnish or rust.