Where the white in a glass tile sits
Most white glass mosaic is not white glass. It is clear or near-clear glass with a white coating on the back, so the color you see has travelled through the thickness of the chip twice before it reaches you.
That is what gives glass its particular white. A glazed ceramic white sits on the surface and stops there; a glass white comes from behind and carries the depth of the material with it, which is why the two never quite match on the same wall.
Iron, and the green edge
Sand contains iron oxide, and standard soda-lime glass carries enough of it to tint the material faintly green. Looked at through the face of a thin chip it is invisible; looked at through the edge, where the light travels the long way, it is obvious.
Makers producing a clean white use low-iron glass, sometimes called ultra clear, in which that iron has been reduced. It costs more and it is the reason two white glass sheets that look identical in a photograph can look like different products on a wall.
Glossy, almost throughout
Glossy carries this range by a long way, with smaller polished, matte, metallic and mixed gloss and matte groups.
Glass arrives glossy; that is simply what the material does when it cools. A matte glass chip has been acid etched or sandblasted afterwards, which scatters the light, softens the white and takes away the depth that makes glass glass. Both are legitimate and they are very different walls.
The sheets and the pencil liners
12x12 sheets carry most of this range, with 11 3/4x11 1/2 and a set of other dimensions behind them, and a group of 0.5x12 pencil liners alongside.
A pencil liner is a narrow strip used as a line: a cap where the tiling stops, a division between two fields, or a border around a panel. The 0.5x12 pieces here are that strip in glass. In glass it does something specific, since a thin bright line of glass against a matte field is one of the few ways to draw an edge without a metal profile.
Matching a glass white to the rest of the kitchen
A white kitchen usually has at least three whites in it already: painted cabinets, a counter and whatever is on the walls.
Glass is a fourth system again, and it runs cooler than a paint white and deeper than a glaze white. The dependable method is a sample held against the actual cabinet door in the kitchen's own light, since the relationship between two whites shifts noticeably between daylight and a warm bulb.
Thickness, and the edge of the field
The chips here run thin, many at around a quarter of an inch or less, against the 3/8 inch that a stone mosaic uses.
That matters wherever white glass runs as a band inside another material, which is one of its commonest uses. It also matters at the end of a run, since a cut glass edge is not meant to be left in the open and usually finishes against a profile or a liner.
Where white glass goes
A kitchen backsplash, a bath surround, a shower wall, a band inside a stone field and a panel behind open shelving. It is the surface people choose when a wall has to be bright and reflective without being a mirror.
Glass mosaic holds the sheets in other colors, glass tile the larger formats, and backsplash tile the other materials for the same wall.
