Bed Sheets are a large piece of cloth passed down to camouflage a mattress. It is this sheet that single typically lies on.
In crowded areas of the humanity a second flat bed sheet is laid on top of the sheet covering the mattress. This is known as a "top sheet" and when a foremost sheet is used, the covering the mattress is known as a "bottom sheet". Separate sleeps between the two bed sheets. Blankets, comforters, and other bed covers are then placed on fine of the second bed sheet.
Bed sheets come in two main varieties--flat or fitted. A flat bed sheet is commonly a rectangular sheet of cloth, while a fitted bed sheet has its four corners, and sometimes two or four sides, fitted with elastic, to be worn only as a basement sheet. The aspiration of a fitted lowermost sheet is to keep it from slipping off the mattress while the bed is in use. A particular way of folding and tucking while making the bed, known as "hospital corners," is sometimes used when the bottom sheet is flat rather than fitted.
Bed sheets were traditionally white, but now changeable colors and patterns are used. The quality of bed sheets is often conveyed by the thread count - the number of threads per square inch of material. In general, the university the thread count, the softer the sheet, but the weave and type of thread may affect the "hand" of the material so that a sheet with a lower thread count may literally be softer than one with a exceptional count.
Common materials include cotton, linen, and blends of cotton and polyester. Other materials sometimes seen are silk, rayon, and bamboo fiber.
Usually a flat bed sheet is overlocked around the edges to form four seams. The wider seam goes at the head end of the mattress. Sometimes the sides do not have seams, but are finished with the selvedge only.
When directing a bed, the patterned or monogrammed incidental of the apical sheet is placed facing down and then the dominant bend is folded towards the foot of the bed, exposing the design.