Window blind

Various window blind styles

A window blind is a type of window covering.^[1] There are many different kinds of window blinds which use a variety of control systems. A typical window blind is made up of several long horizontal or vertical slats of various types of hard material, including wood, plastic or metal which are held together by cords that run through the blind slats. Window blinds can be maneuvered with either a manual or remote control by rotating them from an open position, with slats spaced out, to a closed position where slats overlap and block out most of the light. There are also several types of window coverings, called shades, that use a single piece of soft material instead of slats.

The term window blinds can also be used to describe window coverings generically—in this context window blinds include almost every type of window covering, i.e. shutters, roller blinds, cellular shades (also called honeycomb shades), wood blinds (also called 2 inch horizontals), Roman blinds and standard vertical and horizontal blinds (also called Venetians). In the United Kingdom, awnings are sometimes called blinds or shades.

Overview of different blind types

Window blinds stopper. An old window part to prevent open window blinds from closing. From the Sarona Museum in Israel.

The two overall types of window blinds are ready-made blinds and made to measure. Made-to-measure blinds are made to fit a given or measured window size. Ready-made blinds are manufactured in set sizes that can be cut down to fit any window.

These blinds can be classified broadly into six different categories: roller blinds (which do not have slats but consist of a single piece of material), Roman blinds, pleated blinds, Venetian blinds, Shoji Japanese blinds and vertical blinds.

Many window blinds are made with slats of fabric, metal, plastic, or wood that are adjusted by being rotated from an open position (in which the slats do not overlap) to a closed position (in which they do). Metal window blinds are often used outside of a home or business to protect against theft, temperature, onlookers, glare, bad weather, or fire (in fire-prone areas); often, these blinds are machine-operated, rather than hand-operated.

Horizontal blinds use a thin woven corded "ladder" system to suspend the slats and enable them to be closed or opened via a rotating drum to which each upper end of the woven ladder is wrapped and attached. A lift cord allows the blind to be pulled up and stack tightly to top of the window when desired.

One of the earliest patents for a window shade was filed in 1888, by George L. Castner.^[2]

Vertical blinds use a generally wider slat and one can pull a cord to stack the slats together, to one side, or to separate them in the centre and stack them on each end. The slats can be rotated via a rotating shaft in the upper head rail housing, which runs through independent geared carriers that convert the twisting of a tilt rail to a rotation of each individual slat in synchrony. The original vertical blinds were invented in Kansas City, Missouri by Edward Bopp and Fredrick Bopp, who held the original patent. The company name at the time was Sun Vertical. In the 1960s, the patent and company were sold.

Shoji blinds are based on Japanese 'Shoji' screens and slide on a conventional panel blind track so the panels stack one-in-front of the other- they can stack to either or both sides of the window, inside or outside the recess. They are frequently used as room dividers or wardrobe doors.

The term window blinds is also sometimes used, somewhat inaccurately, to describe window coverings generically—in this context window blinds include almost every type of window covering, including both curtains and blinds for homes and commercial premises, such as bars/pubs, offices, and shops, e.g., Plantation Shutters/Jigsaw Shutters, Roman blinds, roller blinds, and vertical and horizontal blinds.

In Britain, awnings and window shutters are often categorized under blinds, which are so named because they limit observation and thus “blind” the observer to the view. The main types are slat blinds which can be opened in two ways, and solid blinds, which can only be raised or lowered, and are sometimes called shades.

Some types of blinds, such as Holland blinds and woven-wood blinds, have small spaces between the slats. Others, such as pleated shades, have no spaces, because the slats are sewn inside fabric.

Window blinds reduce the heat from sunlight. Ancient Egyptian pharaohs had blinds made of reeds. The most inexpensive blinds in the 19th century were home-made roller blinds, made of cloth.

Window blinds can be manually drawn using a cord, or automated through motorization. Controls for motorized blinds can be from a wall switch or keypad, remote control, or computer, eliminating the need for cords and allowing control of otherwise inaccessible windows. A number of modern homes are integrating blind control with central C-Bus solutions. This control provides ease-of-use and is effective for controlling blind operation to reduce heat loss during winter or minimize heat from the sun during summer.

Varieties

Persian or slat

Persian blind detail, showing how slats are connected

The most common window blinds are Persian blinds, which consist of many horizontal slats, usually of metal or vinyl, connected with string such that they can be rotated to allow light to pass between the slats, rotated up to about 170 degrees to hide the light, or pulled up so that the entire window is clear. Vertical blinds consist of slats of stiffened fabric, plastic, or metal hanging by one end from a track; like the horizontal versions, the slats can be rotated 90 degrees to allow light to pass through or to fold up on one side of a door or window. Vertical blinds are very good at controlling how much natural or exterior light comes into a room, due to the ability of the slats to close tightly.

Venetian

A Venetian blind has horizontal slats, one above another. Venetian blinds are basic slatted blinds made of metal or plastic; wooden slats are sometimes used but in the US these are now usually referred to as wood blinds or bamboo blinds. They are suspended by strips of cloth called tapes, or by cords, by which all slats in unison can be rotated through nearly 180 degrees. The slats can be rotated such that they overlap with one side facing inward and then in the opposite direction such that they overlap with the other side facing inward. Between those extremes, various degrees of separation may be effected between the slats by varying the rotation. There are also lift cords passing through slots in each slat. When these cords are pulled, the bottom of the blind moves upward, causing the lowest slats to press the underside of the next highest slat as the blind is raised. A modern variation of the lift cords combines them with the rotational cords in slots on the two edges of each slat. This avoids the slots otherwise required to allow a slat to rotate despite a lift cord passing through it, thus decreasing the amount of light passing through a closed blind. Slat width can be between 16 and 120 mm, with 25 mm being a common width.

Related patents were taken out in England by Gowin Knight in 1760^[3] and Edward Beran on 11 December 1769,^[4] but Venetian blinds were known to the French long before then. In 1761, St. Peter's Church, Philadelphia had such blinds.^[5]

In the late 19th and early 20th centuries, Venetian blinds were widely adopted in office buildings to regulate light and air. A large modern complex in the US that adopted Venetian blinds was Rockefeller Center’s RCA Building (better known as the Radio City building) in New York City, completed in the 1930s. One of the largest orders for Venetian blinds ever placed was to the Burlington Venetian Blind Co., of Burlington, Vermont, which supplied blinds for the windows of the Empire State Building in New York City.^[6]

In the last few years some companies reinvented the traditional Venetian blind placing it inside the double glass unit of the window. This new type of blind overcomes the problems related to damaging and fouling. Usually magnets are used for motor transmission in order to preserve the sealing inside the insulating glass.

Vertical

Pleated blind

Unlike horizontal blinds, vertical blinds are less likely to collect dust because they stand vertically. Since they draw to the side rather than lifting and lowering, they are easier and faster to operate. They operate better on doors and windows that also slide from side to side. In the 1970s there were few choices of fabric- usually beige or white, which had to have stiffener embedded to prevent fraying, rather like on roller blinds fabric but using a thicker textile.

Vertical blinds became available in flat plastic (PVC), fabric, embossed PVC, faux wood materials, metal, wood and also S-curved slats. A more modern modification is to offer them with woodtrim at top and bottom- sometimes midway as well- and these are usually described as 'Japanese Vertical blinds' because they are often co-ordinated with Japanese style Shoji blinds using the same timber. Vertical blinds were most popular in the UK during the 1990s, since when sales have slowed as they lost popularity with a younger generation.

Stationary vertical blinds are hung in the doorways of some homes and businesses which generally leave the door open. Movement of the blind may signal a change in air flow, or someone entering the doorway. More commonly however, these vertical blinds are made of thick plastic. In the cold rooms of food businesses, this slows the heat leakage into the cold room. In warmer climates, vertical blinds discourage flies and some other insects from entering the building. In certain areas of the UK window blinds are used to disguise the fact that offices have PCs in them and are used as a burglary deterrent.

Materials

Blinds can be made in a variety of materials, some expensive, and some less so. Cheaper blinds are usually made in polyester, aluminum, or PVC. These are inexpensive materials that are all easily accessible and durable at the same time.

A window blind is a means of screening a window, achieving similar results to those obtained by fitting curtains. Blinds are typically the same width and height as the window itself or slightly wider and taller—depending on whether they are fixed inside (Recess) or outside (Facefix) the window's reveal (i.e. the wall recess within which the window itself is fixed).

Window blinds have varying thermal effects: they can block unwanted heat of the summer sun and they can keep in heat in cold weather. But in both of these applications, they also reduce light to varying degrees, depending on the design. Many kinds of blinds attempt varying balances of privacy and shade. Blinds can be made of a number of different materials and manufactured in a number of different ways. This usually determines the name by which the blind is commonly known.

Roller blinds

Stained window glass in the Acropolis Museum (Athens). Rollscreens are SOLTIS 86% screen, black color fabric.

Custom made roller blinds come in blockout, translucent and sunscreen options. They are mounted on a metal headrail and operated with a side chain or spring mechanism. Cheaper and ready made blinds often come with a PVC pole instead of a metal headrail. They are widely used in Spain.

Wood

Wood blinds on an outside window.

Wooden blinds (Venetian blinds)

Wooden blinds are generally known as Venetian blinds. A number of horizontal wooden slats are joined together by corded pulleys which can either gather all the slats at the top of the window to reveal the view or simply angle the slats while allowing some light to travel through the blind yet retaining some level of privacy. Wooden blinds come in a number of finishes (determined by the type of wood used, which ranges from painted to most types of solid oak varieties) and sizes (determined by the width of each slat which is usually available in one of three widths—25 mm, 35 mm or 50 mm). Wooden Venetian blinds are also available as vertical blinds. These are usually made up of wider slats and operate in virtually the same way as their horizontal counterparts (i.e. instead of being drawn upwards to reveal the window, the draw to one side gathering in a vertical bunch).

Pinoleum blinds

Pinoleum blinds are made up of small wooden twigs laid horizontally which are joined together by vertical threading. The resulting weave is, as a result, only flexible vertically and can be drawn upwards once manufactured as a roller blind or in a similar fashion to a Venetian blind. Conservatory blinds are often made with Pinoleum.

In Malaysia, an outdoor blind is sometimes called a "chik". The word was carried over from India by the British during the colonial times.

Safety

Corded window blinds present a strangulation hazard to children, causing 184 deaths in the United States between 1996 and 2012.^[7] Recalls of window covering products have not significantly reduced the number of deaths since 1980. Retrofit kits have been used since 1995 to "reduce" the strangulation hazard; however, children have strangled on retrofit kits since 1995.^[8] In fact, more than 16,000 children in the US were treated in emergency departments for injuries caused by window blinds between 1990 and 2015, an average of almost two children every day, according to a study published Monday in Pediatrics. Although most of those children (93 percent) weren't seriously injured, 271 children died during that time.^[9] The US CPSC recommends using cordless or cord-free window coverings where children live or visit.^[10] For window coverings that use continuous-loop cord systems, like vertical blinds, a wall cord cleat can be used to anchor the cord tightly to the wall and prevent children from having access to the dangling cord loop. Window blinds slats are held together with cords that allow for tilting slats, raising or lowering, and these are potentially dangerous if loose. As an added precaution, cord stops should be installed correctly and adjusted to restrict the movement of inner lift cords.^[11]

Vehicle blinds

Shades on a United Airlines Boeing 747-400.

Some vehicles include or are retrofitted with sun blinds for rear and rear side windows. See also car glass. These blinds are used to protect the vehicle and the passengers from direct sunlight.

Car shades are another common way to protect the vehicle. The shades for the rear and front windows are designed to be unfolded and sit against the window. They can be made of plastic or cardboard. The shades that go on the side windows of a vehicle are usually attached using either suction cups or static cling.

Solid fabric and slat car blinds have given way to cheaper and more flexible, folding, wire-framed "dark-stocking" synthetic blinds. These are used where the car owner has not dark-tinted the glass of the car windows enough, or during the day, by drivers or passengers seeking more privacy.

Most commercial airliners feature window blinds in the passenger cabin. These blinds are generally made of plastic. In a first for the aviation industry, the Boeing 787 Dreamliner lacks window blinds – instead, the airliner features an advanced window dimming system that serves the same purpose.

Gallery

• Some Window Blinds
• 
  Example of 50 mm Aluminium blinds installed in modern stainless steel kitchen
• 
  Close-up of a track blind
• 
  Track Blind
• 
  Blind with horizontal slats
• 
  Detail of turning rod (blind stick) attachment on miniblind
• 
  A roller blind on a door

See also

• Awning
• Curtain
• Domotics
• Mini blind
• Roman shade
• Sudare
• Window shutter
• Window treatment

References

External links

Wikimedia Commons has media related to Window blinds.