There are many styles and sizes of glass shades, many of which are standard. It can be initially confusing trying to figure out the right size and style for your particular fixture or lamp, but here are some guidelines that will assist you in making the right choice.
First tip: Always take measurements from outside edge to outside edge as this is how glass sizes are classified.
Second tip: Remember that glass is undersize. What does this mean? If the glass is classified as a 2 1/4″, or a 7″, the actual measurement of the glass will be slightly less than its stated size.
The first step is to determine how your glass is held in place.
1. Does the glass sit on a table lamp or chandelier that has a round ring or tripod? You probably want a Student shade. Measure the ring, outside edge to outside edge. Standard sizes are 5″, 6″, 7″, 8″, 10″, 12″ and 14″. There is often a place for a chimney to sit within the larger ring. Again, measure that holder, outside edge to outside edge.
2. Is the glass held in place by three screws and does it have a slightly flared neck? If so, measure the cup or holder, outside edge to outside edge.
* If the holder measures just over 2 1/4″, you are looking for 2 1/4″ fitter shades.
* If the holder measures just over 3 1/4″ or 4″, you are looking for 3 1/4″ or 4″ fitter shades. Both sizes come in two styles: either enclosed globes or open shades.
* Glass with 6″, 8″ and 10″ fitters are also available in enclosed globe styles.
3. Do you have a table lamp that has a brass or glass bottom and the glass sits on a ring with no screws? You may be looking for a Gone With The Wind globe. The ring will measure just over 4″ and the globe will have a straight neck that just sits on the ring. There is usually a smaller holder for a Chimney within the larger 4′ ring.
4. Does your glass have a fairly flat opening with no distinct neck? Do you put it on the lamp or fixture around the light bulb socket and then screw a ring around the threaded part of the protruding socket? If so, you are looking for a Neckless shade. Most of these shades have a 1 5/8″ opening.
5. Floor lamps can be very confusing. We have found the most common types to be as follows:
* If your lamp is newer, and you need a glass with a 1 5/8″-1 7/8″ opening, you may need a Neckless shade. The shade is placed on the lamp around the bulb socket, and a ring generally threads around the part of the socket that protrudes.
* Shades on older floor lamps, called Torchieres, have a longish neck that measures 2 3/4″ which fits around an oversize Mogul light bulb socket.
* There is also a very popular floor lamp, dating from the 1950″s, that looks like a torchiere but uses a different type of glass. If your floor lamp has a holder with screws, it will not take the older torchiere style. You need what is called an IES Diffuser glass shade. Often the IES shade supports a fabric shade. IES Diffusers come in three standard sizes: 2 1/4″ fitter with a 6″ top diameter, 2 1/4″ fitter with an 8″ top diameter, and 2 7/8″ fitter with a 10″ top diameter.
6. Chimneys usually sit within several prongs or inside of a round gallery. Again, measure outside edge to outside edge to determine the correct size.
7. Hurricane glass is commonly used on chandeliers and wall sconces. The holder or cup will measure about 1 3/4″ outside edge to outside edge. The glass itself is called a 1 5/8″ fitter, although the actual measurement is closer to 1 1/2″.
Hopefully these tips will help you in determining the proper glass shade for your lamp or fixture. Good luck! Tania Maxwell