What you should know about Glass Mosaic

  Mosaics are fabricated from many small pieces called tesserae. The best glass tesserae are made in Venice (or use the Venetian methodat least) and thus are refered to as Venetian glass smalti. The fabrication process, which dates back for centuries, consists of assembling, cutting, fitting and attaching many, many smalti into the desired design. Each smalto is hand cut (rather chipped) from an orginal “pizza”size sheet of glass which can produced in, literally, thousands of shades. The chipping results in a surface with slight facets.

Both glass mosaics and stone mosaics (or hybrids) can be mounted with various glues, mastics, etc. but by far the most durable mosaics are installed using cement products on a very solid surface, preferbly concrete. Of course, light can not pass through these materials, so all traditional mosaics have to be viewed with reflected light. The facets in the smalti reflect light back to the viewer.

In contrast, stained glass windows are meant to be viewed with transmitted light - the light has to actually pass through the stained glass to the viewer eyes in order for the color and texture of the glass to be appreciated. For this, the light source has to be on the opposite side of the viewer.

     Fabricated and installed correctly, mosaics are some of the most archival artistic media. Under normal conditions, they require NO maintenance. If for some reason they do need cleaning, then a scrub brush with something like Simple Green and a lot of water is all that is needed. Although a well installed mosaic is extremely durable, please do not let anyone use a pressure washer on one!

    

Some characteristics and qualities of glass mosaic are:

  • Spaces between the tesserae (the interstices) are filled with grout making them pretty much weatherproof.

  • They are relatively heavy so should be installed on a very solid substrate. Much of our installation time involves prepping the substrate.

  • Perfect for exterior installations since the colors of the tesserae are permanent and the smalti are very resistant to environmental conditions.

  • Good for floor installations due to the high compressive strength of glass.

  • Perfect solutions for areas in which stained glass windows are wanted but there is not an actual window opening.

  • Good for ceilings, floors, fountains and pools, etc. and can be also installed on curved surfaces such as swimming pools, domes, arches, etc.

  • Best of the mosaic media for traditionally representational work.

  • Shipped to the site usually mounted on paper sections.

  • Several installation methds are used. Ours are normally executed in the indirect method (reverse reading) on a paper cartoon, they are mounted to the final surface with the paper side out. After the cement has partially set, the paper is removed, thus revealing a right-reading design.

  • If installed correctly, they should last 1,000 years. There are no parts that "wear out" or fade.

  • Maintenance is almost nil except for an occasional washing with a brush and soapy water. Again, please no pressure washer.

  • Smalti come in thousands of colors and shades, from very soft, pastel, to very vibrant hues.

  • For additional brilliance, luster and contrast, smalti are available in 23.5 or 24 kt. gold, as well as silver and copper metals.

  • Smalti average 1/4" x 1/2" - they are about 1/4" thick.

  • *NOTE: Usually, when the design calls for a very traditional figurative glass mosaic, we develop the design, then have our associates in Italy, under our direct specifications and supervision, execute it. They are master mosaicisti , and importantly, they have much better access to the 3,000 plus shades of tesserae (smalti) than we do - actually they live just “down the road” from the smalti factory (well, maybe a 4 hr drive!). The completed mosaics are shipped to us - mounted on paper sections and we provide the installation. On really difficult installations, we have the same Italians come over to the States to help us install - we become their assistants!

SOMETHING ABOUT COST

Of the various media in which our studio works, traditional Byzantine style glass mosaics are one of the more costly. There are only a very few fabbrica (factories) in Italy that make true smalti, thus the basic material is difficult to obtain in the United States. The individual tesserae are each hand cut from a relatively small "pancake or pizza" of hand made glass so obviously, they are costly. After the development of the intricate art work (design) that is usually characteristic of a mosaic of this type, the actual execution of the piece requires a great deal of time. A mosaic of 10 sq.ft. could contain about 10,000 tesserae. A project we recently completed in Alabama contained over from 4 - 4.5 million smalti. During smalto fabrication, each piece is handled maybe a couple times. But when it arrives at the studio of mosaicist and the actual mosaic fabrication begins, the selection of each of these smalti represents several decisions and/or manipulations as to size, color and placement. Then most likely the piece has to be cut to a specific shape and mounted directly onto its substrate (or indirectly on paper, for a reverse type of installation). And sometimes this cutting (of a piece of glass 1/2” x 1/4” x 1/4” is done several times to get it just perfect - some times it is even shaped with a grinder. Then the piece has to be affixed to the cartoon using a glue. This is 3-8 separate manipulations to each piece x 4,000,000 pieces! That is a lot of work - but that mosaic will be there as long as the building stands. Mosaics are often installed in very difficult to access locations such as ceilings domes, high arches, etc. At the site, installations can become quite a laborious process so usually a lot of time is necessary. Hopefully you will appreciate that since mosaics are so time consuming, they are costly. There are only a handful of fully qualified mosaicisti, in the world and many of them learned the trade from their grandfathers.