Curtains are often hung on the inside of a building’s windows to block the passage of light, for instance at night to aid sleeping, or to stop light from escaping outside the building (stopping people outside from being able to see inside, often for privacy reasons). In this application, they are also known as “draperies”. Curtains hung over a doorway are known as portières.
Curtains vary according to cleanability, ultraviolet light deterioration, oil and dust retention, noise absorption, fire resistance, and life span. Curtains may be moved by hand, with cords, by press-button pads or remote-controlled computers. They are held out of the way of the window by means of curtain tie-backs. Measuring curtain sizes needed for each window varies greatly according to the type of curtain needed, window size, and type and weight of curtain.
Curtains are a form of window treatment, and complete the overall appearance of the house. Window treatment helps control the ambiance and flow of natural light into the room. The effect of drapery or curtains is best seen in daylight, and with proper indoor light positioning, can look attractive even at night.
Curtains are manufactured from a variety of thick fabrics, each with a differing degree of light absorption and heat insulating qualities. For maximum temperature control, the curtain gap to the window should be small, with minimum convection drafts below or above the curtain. Various architectural structures around the curtain can minimize these air drafts, but usually they are just used for decoration and make rooms feel more cozy.
