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Bedding Glossary

Bedding, Mattress, Sheet Glossary and FAQ

Adjustable Bed

A term used to describe a design of bed that moves, is mobile and/or motorized, and can be adjusted to a number of different positions. Makers of adjustable beds include Craft-matic and Tempur-Pedic, to name a few. For the different styles or types of adjustable beds, see below:

Adj: One-Bottom Adjustable Bed

A term used to refer to an adjustable bed that is comprised of one bottom, or mattress, and that can be adjusted to a number of different positions.

Adj: Dual Bottom Adjustable Bed

A term used to refer to an adjustable bed that is comprised of two bottoms, or mattresses, split entirely into two different mattresses; one mattress for the right side of the bed and one for the left. The mattresses can be adjusted into a number of different positions, giving freedom for both sides to be in a number of different, independent positions.

Adj: Split-Head Adjustable Bed

A term used to refer to an adjustable bed that is comprised of a mattress split only at the head of the bed, while still connected towards the foot of the bed.

Adj: Split-Head & Foot Adjustable Bed

A term used to refer to an adjustable bed that is comprised of a mattress split at the head and foot of the bed, while remaining connected in the middle.

Baffle Box

These are found inside better comforters, especially ones that are down and feather filled. They are three-dimensional boxes that are made of stiffer fabric and allow maximum thickness for the fill while maintaining even distribution of filling within the boxes. They also minimize shifting and migration of fill for maximum comfort and support. Comforters containing a baffle box will last and stay nicer for much longer. This is an essential feature to look for when buying more expensive comforters with better down and feather fill.

Bed Frame

A frame that maintains the position of the foundation, headboard and footboard.

Bed Skirt

A decorative bed accessory often used with a comforter or with bedding collections to finish off a nice, coordinated look. A bed skirt or dust ruffle, covers your box spring and bed frame, and hangs touching the floor or nearly touching the floor.


Also referred to as edging or piping, this is the decorative trim detail on the fold-down portion of a flat sheet or pillowcase or sham, and usually contrasts the bed linen so the detailing stands out.


A combination of two or more different types of fibers woven together to make a distinct cloth. For example, polyester may be blended with cotton so that the sheet is warmer and less wrinkle prone than cotton alone.

Box Spring

A foundation for a mattress that contains springs.


A mechanical fabric finishing process that raises the nap of the fabric, sort-of like combing, giving it a softer feel. For example, flannel is a brushed fabric.

California King

Any mattress, bed frame or foundation that measures 72" wide by 84" long.

California Queen

Any mattress, bed frame or foundation that measures 60” wide by 84” long.


A term used in pillow, comforter and feather bed construction that indicates walls of fabric sewn inside the basic shell that contains down or feather separate from other filled portions, enabling various support characteristics. See baffle box for more information.

Combed Cotton – Cotton than has been through the process combing, which is the separation of long, choice, desirable fibers of the same length from the short, immature fibers. The result is stronger, smoother cotton yarn.


A process for removing all short fibers (those less than 1-1/8") and impurities from cotton that has been carded. Combed yarn is superior to carded yarn in that it is more compact and has fewer projecting fibers. The finest cottons are made from combed yarns. See Cotton for additional information.

Comforter Cover

See: Duvet Cover

Conventional Bed

A term used to describe a bed that is comprised of one flat mattress. Most beds, “normal,” “standard” or “regular,” are a conventional bed. For the purposes of this website, the term “Conventional Bed” is used to distinguish products designed specifically for “regular” beds from that of products designed specifically for adjustable beds.


A term used to describe vegetable seed fiber grown all over the world. The length of the fiber is the major determining factor in the relative quality of the cotton. The best quality cottons are Egyptian, Supima and Pima cottons.


A general term used to describe an ornamental cloth cover for a bed, such as a bedspread.

DoubleUps for Beds (DUFB)

Our company name! Also represents the unique, patented design of our DUFB “split” bed products. Our DUFB products, also known as DoubleUps, are of an innovative, patented design made to revolutionize your bedtime experience. DUFB products are split down the middle (and overlap), so each side offers independent movement and freedom, while still connected by a sew box. DoubleUps solve some of the most common sleep concerns, such as sheet stealing, separate beds, hot vs. cold, tuck in vs. tuck out, sleeping with pets and more. Custom made and adaptable, DoubleUps for Beds are perfect for conventional, specialty and adjustable beds.


An excellent insulator borrowed from waterfowl. These soft, fluffy tufts of down grow under the breast feathers of ducks and geese keeping them comfy no matter what time of year it is.

Down Comforter

A shell filled with small, insulating down feathers. See Down for more information.


A term used to refer to the dept of the mattress, from the tape edge to the center of the upper crown. To determine the size (drop) required for a premium mattress, measure from the lowest tape edge of your mattress to the center of the upper crown, as shown on the illustration below:


Your comforter, no matter the fill, is a duvet.

Duvet Cover

A decorative cover for a duvet (or comforter), designed to protect it and help keep the dirt away. Some comforters need to be professionally dry-cleaned, so keeping your more expensive comforters inside a duvet cover is a smart investment. Duvet covers are a quick way to change the look of a bedroom.

Egyptian Cotton

A long-staple, fine cotton grown chiefly in northern Africa. 100% Egyptian cotton is acknowledged as the best quality, longest-staple cotton in the world. Historically it originated Egypt. The next best cottons are from the Southwest U.S., such as Supima and Pima, which are just a tiny bit shorter than the Egyptian kind. Thread counts range from 200 to 1300. Be aware that the cotton choice presents another area in which labels can be misleading - some may say Egyptian cotton, but in fact may contain only one percent. Look for labels that say 100% or pure Egyptian Cotton.


Feathers contained within a fabric shell and lay on top of a mattress as a mattress topper. The featherbed will normally have elastic straps or even have a fitted sheet on it so that the whole shebang fits over your mattress and stays put. This way you and your featherbed will not find yourselves sliding around.

Featherbed Cover

A large covering for a featherbed to protect it from body oils and dirt that also helps the featherbed to last longer.

Fill Power

The measurement in cubic inches that one ounce of down will fill when placed in a glass tube and allowed to loft for up to three days.

Fitted Sheet

Also called the “bottom sheet”, a fitted sheet fits tightly over the mattress. Fitted sheets usually have corners with elastic sewn around the edges. The cheaper versions will feature elastic on only two sides, while better quality fitted sheets will have elastic all the way around the bed. This helps keep the fitted sheet on the bed so you don't wake up on the floor.

Flat Sheet

Also called the "top sheet", a flat sheet is placed on top of the fitted sheet and is typically tucked-in around the mattress at the sides and the foot.


Fiber of the flax plant is made into thread and woven into linen fabric.


Any mattress, bed frame or foundation that measures 54" wide by 76" long.

Full 80" Long

Any mattress, bed frame or foundation that measures 54" wide by 80" long.


A triangle insert that adds strength to edges and corners (such as a seam).


Items that are reinforced with gussets.


Refers to how you would describe the feel of a fabric, such as soft, cool, fine, still and the like. An example would be, “The linens provide for a soft hand.”


A decorative stitch usually bordering a hem made by drawing out several parallel threads and catching together the cross threads in uniform groups. Used for embroidering sheets and pillowcases.


A term used to describe objects that have a decreased likelihood of provoking an allergic reaction.


Any mattress, bed frame or foundation that measures 76" wide by 80" long.


Fabric woven from flax.


The actual sleep surface of the bed. The mattress supplies a bed’s support, firmness and comfort.

Memory Foam

A type of elastic, viscous synthetic foam with exceptional contouring abilities.


A plain-weave fabric made of cotton or poly/cotton blends not less than 128 threads per square inch. Muslin typically will not last too long for use in bed linen. Sooner or later you will be able to see right through muslin.

Open Construction

A term used to describe comforter construction where the filling is allowed to move around. This will prove to be a poor choice in the long run. The comforter will get lumps of fill in the corners and then get thin in the middle where you would like to have it most. The fill will get smashed down and not be able to keep you as warm as when it was new. Typically, you will also find that the shell on such a comforter will be made with a less-tight weave, meaning that before you know it, you will have annoying little feathers poking you here and there.


A smooth, flat, closely woven and combed fabric that comes in 100% cotton or 50/50 cotton/polyester blends. Being finer than muslin, you can expect thread counts to range from 180 to 250.


The tendency of fibers in bedding like sheets to eventually work loose from the sheet surface and form little balls that remain attached to the surface of the fabric. You will typically find pilling in bedding with lower thread counts. If you want to avoid pilling, choose thread counts of about 180 or more, generally speaking.

Pillow Case

A functional pillow covering to protect your pillow from body oils and soiling. It is a good idea to have several pillowcases so that you always have a nice, clean fresh one on the bed.

Pillow Protector

A zippered cover designed to protect pillows. This keeps the pillow fresh and away from body oils, fluids and potential stains, preserving the life of the pillow. Make sure a pillowcase is used over the pillow protector.

Pillow Sham

A decorative fabric cover for a pillow usually constructed with a flange or trim.

Plied Yarns

Yarns that are twisted together after spinning to create a new yarn. Plied yarns do not increase the durability or strength of the fabric and will exhibit a different feel, or hand, than a cloth woven with single yarns. Plied yarns should be counted as only one yarn.


A man-made synthetic fiber. Durable, wrinkle and shrink resistant, and non-breathable. Polyester fibers are often blended with cotton or other fibers to produce blended cloth.


Most pre-shrinking of cotton cloth is done on a compressive shrinkage range which is a mechanical process that allows cotton cloth to shrink naturally in its length. There is minimal residual shrinkage after this process.


This is the image, illustration or pattern applied or transferred to the cloth. You will find an absolutely huge variety of patterns on any and all bedding. Thin or thick stripes, geometric patterns, flowers or any other image or picture on bed linens and bedding is called a print.

Queen Size

Any mattress, bed frame or foundation that measures 60" wide by 80" long.


A weave construction for mercerized cotton fabrics, which produces a smooth, lustrous surface.

Sateen Weave

A weave that has more yarn surface on the face of the cloth than other basic weaves, giving a softer hand and more lustrous, shiny look. Cloths made with combed yarns are usually mercerized and have a very smooth, lustrous surface effect.


A fabric (as of silk) in satin weave with a lustrous face and dull back.

Sew Box

Used on our patented DUFB “split” products, the sew box is located towards the foot of the bed and connects the right and left side of the sheets and/or comforters. This allows for the sheets to remain connected while still offering independent movement and freedom. For more information, see DoubleUps for Beds.


An ornamental covering for a pillow.


The contraction of a fiber, yarn or fabric after washing and drying. All products made of natural fibers have a tendency to shrink 4%-8%.

Supima or Pima Cotton

High quality cotton whose long fiber staple is somewhat equivalent to Egyptian cotton. Egyptian cotton is grown along the Nile River whereas Pima is grown in the southwestern part of America. Supima is made from extra-long staple Pima. The soft hand feel of Supima and Pima make them very desirable choice for bedding. Expect to find thread counts to range from 200 to 1000.


A term to describe any material that is artificially created (i.e., not found in nature).

Thread Count

The number of yarns per square inch in a woven fabric. The higher the count is, the finer the fabric. It is simply a measure of how many threads—warp (lengthwise) and weft (crosswise) - are woven into one square inch of fabric. The thread count of “standard” cotton or muslin is around 150. Good quality sheets start at 180-thread count, and a count of 200 or higher is considered percale.


A very durable striped linen or cotton fabric with a twill weave. This closely woven material is primarily used for mattress and pillow coverings.


Any mattress, bed frame or foundation that measures 39" wide by 76" long.

Twin 80" Long

Any mattress, bed frame or foundation that measures 39" wide by 80" long.


The characteristics of a material that combine viscous and elastic behaviors. The scientific term used to describe memory foam.

Warp Yarns (Threads)

The lengthwise yarns that of any woven fabric.

Weft Yarns (Threads)

The crosswise yarns of any woven fabric.