What is Vitreous Glass?

The term “vitreous glass” is used to refer to a type of glass which is popular for mosaic tilework. This type of glass is durable, able to withstand chemicals and the elements, and comes in an array of colors which can be used for many different types of projects. Many tile and glass stores sell vitreous glass, and this type of glass can also be ordered directly from companies which make it or from companies which stock mosaic supplies.

The word “vitreous” actually literally means “glasslike,” so “vitreous glass” is a bit of a misnomer. Glass, by nature, is vitreous. When people refer to a particular glass product as vitreous glass, they usually mean that the glass is hard, durable, a bit grainy in texture, and easy to cut. This makes it very suitable for mosaic applications, in which cutability and durability are very important traits for the glass to have.

Many types of this glass are opaque, although translucent and swirled versions are also available. The glass is usually textured on one side so that it will stick to the adhesive used to place it, and the upper surface is smooth. Commercial vitreous glass which has been precut will have smoothed edges, and when glass is cut for custom applications, the edges can also be smoothed so that the glass will be less likely to cut people.

One form of vitreous-type glass is smalti, which is sometimes still made in the traditional way, with the glass being poured out in flat sheets, allowed to cool, and then cut to size. Other types of molded, extruded, or produced on rollers. These glass pieces can vary in thickness. Thinner glass may not be appropriate for walkways, while thicker glass may hold up fine, especially if it is well supported and properly grouted so that the weight of passerby is distributed, rather than concentrated.

There are some special effects which can be achieved with the glass. Some companies make metallic glass with metal flakes in it, or opalescent glass which changes color depending on the angle at which it is viewed. These features can be desirable in mosaic tesserae when people want to add depth, complexity, and texture to an art project. Regular vitreous glass also comes in matte, semigloss, and high gloss versions which can be used in a variety of different settings and applications. Many companies are happy to send samples of their glass to people who are interested in placing an order, so that people can determine whether or not the glass will meet their needs.