technical help #1
technical help #1
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Stained glass can be subdivided into three major groups:
(I) MACHINE MADE
(sometimes referred to as cathedral glass which all people who now read these pearls of wisdom will know is not entirely correct).
Machine made glass is produced almost entirely by mechanized processes with little hand manipulation (except on payday when cheque writing). Because of this, MMG is uniform in texture, thickness and colour. Most manufacturers start with several pots of molten glass- each pot being a different colour (but not charteuse- everybody hates chartreuse) Varying amounts of each pot's glass is gathered in large cast iron spoons, and carried to a table, where they are mixed according to how the mixer's home life went the previous evening and then run through a set of rollers, both usually smooth. If a texture is wanted then a roller with that texture replaces the bottom roller
We classify MMG by its ability to transmit light ;
1) Cathedral Glass- totally transparent (totally, man) but not necessarily without colour.
2) Opalescent (Opal)- totally opaque (not transparent). Done by usually adding fluorine to the molten mix.
3) Streaky (Wispy) Opal or Cathedral- a combination of the above two.
MMG is almost exclusively a North American (read U.S.) phenomenon (like guns, Letterman and Balloon Boy), with the invention of opalescent glass primarily attributed to two really cool guys called John Lafarge and Louis Comfort Tiffany (wow, what was Louis' dad thinking when he gave him that middle name, eh?). Manufacturers at Fantasy In Glass that fall into this group; Kokomo, Optimum, Spectrum, Swiss Cheesed, Vegla, and Wissmach.
(II) FULL ANTIQUE
Now here's where it gets a little harder to follow so read slowly.
This glass is made entirely by hand and mouth (hopefully without mixing the two up). There is virtually no mechanical or governmental assistance, with the process aided along by the ingestion of copious amounts of varying liquids. This process has remained virtually unchanged for hundreds of years (tho' the beer's not nearly as good anymore).
Antique glass begins as a molten gather of glass on the end of a glassblower's pipe. It is continually manipulated, prodded and poked until shaped into a large balloon approximately 12" across by 24" deep. The 'head' and 'tail' are cut off, leaving a cylinder that is cooled overnight (all that manipulation requires a mandatory 24 hour cooling off period). The next day, this cylinder is cut, and then put back into the kiln to soften and open up into a sheet approximately 24" by 36". Full antique glass, as a rule, is transparent with no "opalizing". Because of the unique way in which it is produced, antique glass is not uniform in thickness (and therefore, colour) and texture (which is added in the shaping process)
Manufacturers at Fantasy In Glass that fall into this group; Desag, Fischer, Fremont, Lamberts, and St. Gobain (a company started by old Louis XIV to provide glass for the Versailles Palace 'cause apparently he couldn't find a good supply of ceiling mirrors)
(III) ART GLASS
Now it really starts to get weird. The unique thing about this group is that it is unique. Production techniques arise out of experimentation, the attitude of the craftspeople, the availability of raw materials, the mood of the accountant, the position of the stars, etc. This is the Ferrari of stained glass- exotic, temperamental, and often expensive. Good old Louis Tiffany, (the guy with that bizarre middle name) aside from pioneering the copper foil technique, gets full credit with having invented several original and unique glass types in this category- catspaw opal, ring mottle, heavy ripple, drapery, fracture and fracture/streamer glasses and amazingly, all this was accomplished without the use of illicit mind altering pharmaceuticals. With the closing of Tiffany's studios and the backlash against the ornamental arts of the Art Nouveau era these glass types went the way of the lava lamp- they were viewed upon as tacky and in bad taste (thank heavens that's never happened to my velvet Elvis collection- Elvis the Early Years). Many formulas from Tiffany's glass furnaces were forgotten and lost. Manufacturers turned to other more popular glass types (like sneeze guards for salad bars) and these unique glasses weren't made for many years.
In the late Sixties, predominately on the west coast of the U.S., a group of glassblowers began to increasingly experiment with various formulas (some even in glass), and began rolling glass into sheets using small hand made rolling tables, and trying unorthodox techniques not previously thought of in glass production. These modern day pioneers reinvented many glass types not seen for decades, as well as adding a few new ones.
To describe how art glass is made is a tough question to answer as can be seen from above. This group is only classified as such, because most of its production techniques do not follow accepted practices. Quite often, a small cold table is used (i.e. in catspaw opal production) remaining stationary, while a roller passes over it. This results in the glass sheet remaining in contact with the cool table for a several moments (bad glass manufacturer!), causing the glass to "strike" or change colour and/or density as the sheet contracts and "puckers up" creating the recognizable catspaw effect. Art glass therefore has only unique characteristics. It cannot be easily classified so we wimp out and call it Art glass.
Manufacturers at Fantasy In Glass that fall into this group; Bullseye, Chicago Art Glass, Kokomo, Oceana, Schlitz, Uroboros and Youghiogheny.
Glass 101