Sheer fabric is fabric which is made using thin thread and/or low density of knit and which results in a semi-transparent and flimsy cloth. Some fabrics become transparent when wet.
The sheerness of a fabric is expressed as a numerical denier which ranges from 3 (extremely rare, very thin, barely visible) to 15 (standard sheer for stockings) up to 30 (semi opaque) until 100 (opaque). The materials which can be made translucent include gossamer, silk, rayon or nylon. Sheer fabric comes in a wide variety of colors, but for curtains white and shades of white, such as cream, winter white, eggshell, and ivory are popular. In some cases, sheer fabric is embellished with embroidered patterns or designs.
A common use for sheer fabric is in curtains, which allows for sunlight to pass through during daylight, while maintaining a level of privacy. Due to the loose weave in sheer fabrics curtains offer little heat insulation. However, when it is lighter on the inside of a room than it is on the outside (such as at nighttime), then the inside of the room can be seen from the outside.