Window coverings have been developed to combat the loss of heat through glass -- a notoriously poor insulator. As much as 50 percent of our home-heating bills can be cut by window coverings that fit tightly at the edges of a window and cover the glazed area securely.

Conventional curtains can, of course, be splended insulators. They are hung to cover the windows from wall to wall, they can blanket the space securely from even the coldest draft.

But viable alternatives to curtains are now available, and the first of these are quilted window shades. These ingenious devices are a five-layered sandwich of polyester fiberfill and aluminum foil, covered with white, quilted polyester in several quilting designs.

The foil acts as a moisture and vapor barrier and reflects heat. The fabric is on a spring roller for easy ups and downs, and the sides of the quilt slip through a plastic track that is fixed to the window frame, creating a secure barrier.

Washable and dryable, this thermal shade stores up the sun's heat by day and keeps the glazed areas cozy at night. The sade can be pulled down during the day in the summer, to block the sun's heat.

I used these quilted shades in a living room with two conventional double-hung windows. The walls were painted in a plae gray, a bit lighter than the wall-to-wall pearl gray carpet.

Off-white velour uphostery on the modular seating pieces and a white marble-topped coffee table repeat the white of the quilted shades. I framed these with natural raw wood in a deep wood box, to which the sahde's vertical runners are fixed.

The antique hutch between the two windows was reduced to its natural fruitwood and waxed. It now reflects lamplight and shows off a collection of white Limoges china.

To finish the windows, I used an inexpensive pair of two-panel hinged screens of natural rattan on the outer side of each window, repeating the natural wood of the frames and hutch. Behind each is a floor-based floodlight, converting the screens into giant, textured lighting fixtures at night, and subtly accenting the quilted comfort of the shades.

The only objection to the shades is their initial cost, between $60-$100 for the average-sized window. This can be a "saving," of course, because of the lower fuel bills you'll receive.

If you want a more economic alternative, however, simply use the 79 cent sheets of transparent plastic, offered as "indoor storm windows," at your local home center or hardware store. Fix the sheets to the windows with caulking compound -- now available to rolls of different colors -- to seal out drafts.

Combined with matchstick blind roll-up shades -- or just the hinged, textured screenns in front of the window area -- they are a a fine alternative. tThe plastic won't keep out as much cold but the cost will be far lower.