Cellular shades. These single-, double-, and triple-celled shades, with their honeycomb design, evolved from the plain pleated shade and are used in much the same way. Their main advantage is energy efficiency, since the pockets trap air. But don't expect a cellular shade to solve your energy problems if your window is drafty and you keep the shade raised or allow light gaps.
Pleat sizes range from 3⁄8 to 2 inches, and color and texture options are constantly increasing. Light choices range from sheer to opaque. Like plain pleated shades, some cellular ones have a dual-light option, switching from a translucent to an opaque material on the same shade. Also like pleateds, you can get ones that stack at the bottom or meet in the middle. Some cellular shades that stack at the top are cordless: you just push up or pull down on the bottom bar to move the shade.
In addition to being used in standard windows, cellular shades are often custom-fitted to angle-top, arched, and other odd-shaped windows. They can also be used in the same way as pleated shades in skylights. Though cellular shades are almost always set horizontally, they can be positioned vertically, as they sometimes are on sliding glass doors.
Roller shades. Used alone or in conjunction with other window treatments that are sheer or don't cover the entire window, roller shades
provide privacy and block light when pulled down, but they are unobtrusive when rolled up.
If you want a reverse roll (the shade pulls down from the front of the roller), you must specify it. A reverse roll hides the roller and allows an inside-mount shade to sit flush with the window casing.
The operating mechanism is either a standard spring roller or a bead chain, which stops the shade in any position. A bead chain keeps the shade cleaner since you touch only the chain and not the fabric. The chain also makes it easy to raise and lower heavy or hard-to-reach shades.
Custom roller shades are usually made from cotton, linen, or other tightly woven fabrics. Much of their appeal rests in the choice of a decorative hem and shade pull.
Most stock shades are vinyl. Several companies offer inexpensive shades that you can easily size yourself to fit a window. Just slide the adjustable roller to your window's width, strip off excess shade material (tear along scoring in the vinyl), and press the material to the roller. Some brands are plain white, while others offer some choice in color and pattern.