|Tiffany lamps, like all his other work in glass, were craftsman-made luxury items and were expensive in their own time - 100 dollars each for the popular standard lamps. Yet, such was their appeal that no well-off American who claimed to live in any could exist without owning at least one genuine antique Tiffany lamp. And, those among the aristocracy and nouveau riche in Europe who professed to appreciate the attractions of Art Nouveau bought Tiffany lamps, vases and other items of art glass in quite considerable quantities from the shop in Paris, La Maison de l' Art Nouveau, which gave its name to the movement.
Tiffany's technique for introducing color into the glass came to be known as "favrile", or by hand, and became his patent. The Tiffany lamp glass was quite different from the traditional stained glass that had been used for centuries in Europe. The Tiffany technique involves spraying a vaporized solution of salts and iron or tin on the foundation glass after reheating. While the piece is still malleable, it is reheated and sprayed with metallic vapors. These vapors are absorbed by the molten glass which forms layers of reflecting color when the glass is cooled and set. Copper spray gives colors ranging from greenish-blue to ruby-red, whereas cobalt vapor produces a range of blue shades and if mixed with manganese produces a deep black.
A very high standard was required of all Tiffany lamp workers. Arthur Nash, a worker at Tiffany Glass and Decorating Company, further developed and perfected Tiffany's work on Favrile glass. As a result, Nash was the only glassblower Tiffany employed that was allowed to sign Tiffany's own work.
The designers of antique Tiffany lamps always gave them a constant theme, such that the metal base and pillar was as relished as the magnificently colored Tiffany glass shade. Tiffany lamps touted designs of bronze depicting dragonflies, spider's webs, water lilies, peacocks, and turtle shells. The Wisteria lamp is likely the most coveted Tiffany lamp by collectors with its draping blue glass and bronze tree trunk base. There are many Tiffany lamp reproductions; most, but not all, authentic Tiffany lamps are marked with "Tiffany Studios" on the base.