When purchasing insulating curtains, it is a good idea to inspect them before buying. Physically handling and feeling the weight of the fabric will typically give you a better idea of how much insulation they will provide. For this reason, if you plan to order online, make sure the merchant has a clearly defined return policy. In addition, you will need to decide if you want insulating curtains that are in one piece or the double-layered variety. Typically, double-layered insulating curtains provide more options in terms of color and print.
Double-layered or double-hung insulating curtains are generally more popular, because the insulated drapery hangs behind another drapery and is not visible. The insulated panels should ideally be constructed of thermal fabric that is meant to keep outside elements from penetrating through the windows and window seals. Generally, the heavier their weight, the better insulation they will provide.
In most cases, the tightness of the weave and the thread count of the fabric is a good indicator of how well a fabric will insulate. Fabrics with loose weaves usually will not provide as much protection as tightly woven fabrics. In some cases, heavier fabrics that are loosely woven would not provide as much insulation as a lighter weight fabric with a less penetrable weave.
Fabrics that tend to work well for double-hung insulating curtains include wool, heavy silk, and mohair. In addition, synthetic fabrics blended with a component called polypropylene are also considered good insulators. Generally, these fabrics are used as the under layer of the drapery, which leaves you free to choose any type of covering drapery you like.
Some insulating curtains can be purchased as a single layer, with the insulating component being bonded to the interior of the drapery. This type of insulating curtain will only require one set of hardware per window, so their expense could be slightly offset by the money you may save on curtain rods and attachments. You may find, however, that these curtains are somewhat limited in size, color, and fabric design, and no matter the fabric content, a single layer of insulation usually does not provide as much protection as double layers.
Room décor is usually an important consideration when purchasing any type of draperies, including insulating curtains. If your room décor is designed around an airy open theme, insulated curtains may spoil the effect. In this type of situation, you will need to evaluate whether the cost of your particular taste in interior decorating is worth the money that insulated curtains might eventually save.