Louis Comfort Tiffany is as famous for his legendary store as he is for the lampshades he began to create in the late 1800s. His first lampshades were made of blown glass and exhibited for the world at the 1893 World's Columbian Exhibition in Chicago. Five years later, Tiffany began making his lampshades in leaded glass. Genuine Tiffany lampshades can sell for thousands of dollars, and some have even sold for millions. Because of the expense, most people opt for authentic-looking reproductions. However, if you want to purchase real Tiffany lamps, it is in your best interest to know the signs of an impostor.
Know the correct time period and look of original Tiffany lamps. Tiffany lamps were created during the mid-1890s through the 1930s by L.C. Tiffany & Associated Artists, L.C. Tiffany & Co. or the Tiffany Studios in New York. Original Tiffany lamps were hand-crafted and usually not consistently marked because of this. Look for high-quality materials and superb craftsmanship. If the lamp contains shoddy work or poor-quality metals or cheap glass, it would be safe to assume that the Tiffany lamp is not real.
Look at the makers' marks. While some lamps were not marked, most were. In fact, the majority of the lamp bases were marked with both the TGDCO logo and TIFFANY STUDIOS NEW YORK. If the base of the lamp does not have both text and logo, it is probably a fake. Also, original lamps were marked with letters and numerals in a single line that are the same height. If the text on the lamp is not identical in height, the lamp is probably not an original Tiffany.
Check if the markers are of the same patina (or coloring) as the surrounding area. If the marker appears fresh, it is probably a fake lamp. Also, if the markers contain any lowercase letters or hooks or accents to the letters, it is probably an impostor. Original Tiffany lamps contain text in all capital letters and are written in simple lettering without all of the hooks and accents found in most text. For example, the "T" in "Tiffany" should be two plain bars without any embellishments.
Look for applied antique coloring to the glass of the lampshade. Sometimes coloring is applied to faux lamps in order to make them look older than they are and give them an authentic or antique look. To be sure the coloring is natural, dip a cotton swab in nail polish remover and swipe the lampshade. If anything other than dirt and grime appears on the swab, the lamp is not real.
Look for cracks in the glass. Genuine and antique lamps have loose elements and will have some cracks in the glass of the lampshade. If the lamp is crack-free and does not rattle when gently shaken, it may not be real.