A blanket sleeper is a type of pajama styled as a one-piece garment, designed for warmth and ease of donning. The blanket sleeper is very popular during the colder months in colder climates, especially in North America. Occasionally, these are referred to as "footed pajamas", though that term can refer to two-piece garments as well as one-piece garments; an older term is "Doctor Dentons", after a famous manufacturer of blanket sleepers.

Appearing similar to a loose coverall, the blanket sleeper has long arms and long legs, and is typically closed with a zipper in the front (either extending to the crotch of the garment or down one leg to the ankle); many styles feature attached feet. These can be made from a variety of fabrics, but are most often made from synthetic fleece. Though usually classified as children's wear - and a popular choice for clothing infants - sizes range from the smallest infant to the largest adult, though with adult styles styled more for women than men.

Infant's Styles

These are often made from cotton fabrics such as terrycloth, but can be made from synthetic fleece as well. Often, the sleeper is decorated with cartoon or nursery-rhyme characters, and occasionally embroidery. These often close down the front to the crotch with snaps or zippers. However, the inside seams of the legs are often closed with snaps instead of sewn closed, to ease diaper changes. The feet are made of the same fabric as the rest of the sleeper. These are used as all-purpose clothing at this age.

Children's Styles

These are most frequently made from synthetic fleece; the soles of the feet are typically plastic-covered (to provide additional protection and longer wear) and often include toe caps (extensions of the plastic sole designed to protect the toes). As with the infant's styles, these are often decorated with cartoon characters. Zippers extend to either crotch or ankle; often, a fabric tab covers the top of the zipper to prevent scratches. Up until the 1960's, these sleepers frequently featured a "drop seat" - a flap of fabric, closed with buttons or snaps, that the wearer could release to use the toilet without removing the sleeper. More recent designs usually forgo the "drop seat", but custom designs often include it. The blanket sleeper is often used as a type of playsuit at this age, as well as sleepwear.

Adult's Styles

These are made from a variety of fabrics, with terrycloth, flannel, and synthetic fleece predominating. Feet may or may not be attached; if present, feet are often made of the same fabric as the rest of the sleeper, though occasionally plastic soles are attached. As these are typically sold to women, pastel colors and flowery prints are most common, though seasonal prints (such as snowflakes) are also popular. The front opening extends to the crotch and is typically closed with a zipper, though some close with snaps or buttons. Some styles include a "drop seat" or a hood. At this age, the blanket sleeper is typically used as sleepwear, although it also is used as part of a type of ageplay known as infantilism or the more common acronym ABDL.

Pajamas Definition