Great Windows Glossary

In order to make your decision and shopping experience as easy as possible, we want to share our knowledge and design expertise about window blinds and shades with you. Here we can help you select the perfect window blinds and shades, teach you how to measure for window shutters or mini blinds correctly, help you understand the differences in Great Windows' products, inform you about care and maintenance of your windows blinds and shades, and much more. Simply click on the area of interest below and we will tell you everything you need to know.
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Accent Rod
A decorative bar that fits through the bottom of the scalloped and tabbed hems on our roller shades.
A slight variation from the exact measurements of the window, usually decreasing them slightly. It is industry standards to take this to allow for anticipated needs.
Aluminum Blinds
A window blind made of horizontal slats of curved aluminum. Also called mini-blinds, micro-blinds, or macro-blinds.
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Wood with a light weight and fine grain. Considered a premium wood for use in horizontal blinds or shutters.
Blackout Liner
An optional white backing available on some products. Ensures total light blockage and complete privacy.
A window covering designed of either horizontal or vertical slats. Blinds can be made of wood, aluminum, fabric, or synthetic materials. Horizontal blinds traditionally open from the bottom up; vertical blinds open and close to the side.
Bottom Rail
The bottom-most slat on a horizontal blind. It is often weighted or thicker to guarantee that the blind will hang properly.
A form of hardware that serves as both a functional and a decorative element. Brackets may be used as blind, shade, or rod supports.
C Top  
Cafe Shutter
A shutter that covers only the bottom half of the window.
Small devices in the headrail of vertical blinds that attach the vanes to the headrail.
Ceiling Mount
A product is mounted to the ceiling, or top of the window. This eliminates the gap between the blinds or shades and the ceiling.
Cellular Shades
See Honeycomb Shades
Center Support Bracket
An extra bracket placed in the center of a window treatment to support extra weight and avoid sagging.
Channel Panel
A clear vinyl sleeve (white backing) that a fabric vertical blind is inserted to give the vane a solid vinyl backing. It pairs the height and weight of vinyl with the stylish appearance of fabric.
Cloth Tape
Runs vertically along the blind, and holds the slats together. It is available in a variety of cotton twill and decorative cloths, and replaces the standard cord ladder.
Contempo Hem
A decorative hem for a roller shade that allows the fabric to be wrapped around an aluminum rail and enclosed with end caps for a clean and contemporary finish. The aluminum rail also adds weight which allows the shade to hang flatly.
Continuous Loop
Rotates on a clutch to smoothly raise and lower even the largest shade.
Continuous Valance
A single valance covering two or more blinds.
Cords, wands (plastic mechanisms that are twisted to open or close blinds), or chains that allow you to open, close, tilt, raise, or lower blinds.
Control Locations
The position of the cord, wand, or chain that controls the product. Standard placement is on the right side, but they can be located on either side.
Cord Cleat
A small plastic anchor that attaches to your wall and holds excess cord.
Cordless Duofold
Eliminates all cords! Allows for privacy and light control. Shades can be manually raised from the bottom or manually lowered from the top.
Cordless Lift
Cordless Lift - Eliminates all cords! The Cordless Lift option is engineered so you can manually lift and lower with exceptional ease.
Cord Lock
The mechanism that acts as a "brake", locking shades, e.g. honeycomb shades, at a desired position.
A decorative board, often molded or painted, that is attached to the top of a window to create an architectural finish. It can be used with or without a curtain.
Door shutter is cut to allow room for a levered handle.
D Top  
Decorative Hem
An optional upgrade on roller shades. They come in a wide variety of designs, some with fringe and some with accent rods. A straight hem is standard.
Decorative Valance
An optional upgrade on most products that adds a decorative element. A basic valance comes standard.
The distance from the front of edge of a window to the back, or pane of glass. This is the mounting space within the window.
A method of controlling the light entering through the window, where the window covering bends the light entering it, causing it to disperse.
Divider Rail
Stationary piece of wood that separates top louvers from bottom louvers. This feature allows the user to open top louvers to allow light to come through without compromising privacy.
An operating option that allows more privacy by giving users a choice of opening window shades from the bottom up (the traditional method), or from the top down (permitting light to enter without giving up any privacy).
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Easylift Headrail
An operating mechanism that uses looped cords instead of tassels to make wider shades easier to raise and lower. The Easylift can be used on all shade widths, but is recommended for widths greater than 72 inches.
Edge Binding
Solid and decorative edge bindings give natural roman shades and panel tracks a more tailored finish that accent, contrast or add pattern.
Extension Brackets
Optional brackets that are used in order to clear any obstructions a window may have (door knobs, trim, etc).
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Factory Deduction
The factory automatically trims off a certain amount of an inside-mount blind or shade to ensure that it will fit. The amount taken off varies depending on the product.
Fenestration Data
An architectual/ engineering term used in describing the data used in proportioning of windows and the factors that influence the admittance of energy through the glass and its effect on the building interior.
First Tier Outside Mount
A point of measurement. For width, the outer edge of innermost flat surface on left to same on right. For length, the top edge of the innermost flat surface to sill.
Flush Inside Mount
The product fits completely inside the window frame, flush against it, when installed. A minimum depth is needed, which varies depending on the product. Also called a recessed mount.
Free Hanging
The vanes on vertical blinds are not inserted or placed in clear plastic sleeves. They are allowed to hang freely and often have a small weight in their hem to keep the fabric taut.
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To glaze a window is to furnish it with a gloss or other material. The glass or other material may then be referred to as the glazing material. When drapes or other heat control devices are used in combination with the glass, the conbination is referred to as the glazing system.
A narrow flat braid or rounded cord of fabric used for trimming.
H Top  
The top of a shade or blind that holds the components for operation.
Heat Transfer
The amount of heat that travels from the inside of the window to the outside, or vice versa. Used to determine energy efficiency: the lower the heat transfer, the more a product can lower energy costs.
The distance from the top to the bottom of the window. Can include the window frame or not, depending on whether it is inside mount or outside mount.
Horizontal pleats are added to the fabric of roman shades for fullness.
Hold-Down Bracket or Clip
Optional brackets that secure the bottom rail, and keep it from swinging out or being raised. Often used on doors.
Honeycomb shade
A style of pleated, fabric shades comprised of honeycomb-shaded cells.
Horizontal Blind
A blind in which the slats run horizontally, rather than vertically, and can be tilted and lifted.
I Top  
Inside Mount
A point of measurement at the innermost part of the window frame where a window treatment is being mounted.
L Top  
An L-shaped metal bracket used to mount products to walls, window trims, or moldings. Also called an Angle Iron.
Cording that runs vertically through a horizontal blind, holding the slats together.
Looped Control
Offers alternative functionality to the spring loaded roller; allows you to raise and lower your shade with the smooth operation of a beaded chain loop.
Lift Cord
The cord that raises and lowers the blind.
Movable wood or vinyl horizontal slats in a framed opening.
M Top  
See Aluminum Blinds
The technique of using a diagonal seam to join two pieces together at a corner. Used on valances.
Motorized Blinds
Eliminates the need for controls. Rather, the blind can be raised, lowered, or tilted using a remote, wall switch, or preset timer.
Mounting Bracket
Plastic or metal devices that are used to attach your product to the wall, window frame, or molding.
A vertical strip of wood that divides the panels of glass in a window.
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Natural Roman Shades
A natural woven wood shade made from bamboo or grasses.
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One-Way Stack
Vertical blinds that open in only one direction, and stack on one side.
A term used to describe window treatments that do not allow light through their fabric.
Openness Factor
Refers to the ratio of open or interstice area to the total flat surface area of a drapery fabric or perforated material. This quantity relates well to the amount of solar heat admitted through a fabric or perforated material and to the extent to which discomfort results to individuals near the glazing system.
Outside Mount
A point of measurement, typically the outer edge of the beveled trim of a window.
P Top  
Pleated Shades
Similar to honeycomb shades, these are made of fabric with evenly spaced horizontal pleats. Vertical cords can be seen running through them. They are a less expensive alternative to honeycomb shades.
The distance that a window covering extends into the room, away from the wall.
R Top  
Similar to heat transfer, this measures a product's ability resist heat loss. The better the R-value, the more insular and energy efficient the product is.
The opening in which the window has been installed.
The distance from where the design starts, to where it starts a second time.
The part of a curtain or valance that wraps back to the wall.
Reverse Roll
Standard Roller Shades have the fabric rolling off the back of the shade. Reverse Roll shades have the fabric rolling off the front of the shades. This application is usually chosen with blackout materials so that the different color blackout material will not show on the roll ( roll and body fabric will match).
Roller Shade
A simple cylinder shade that can be operated by spring, beaded chain, or cord loop, and coils up when raised.
Roller Shade Width
The roller shade fabrics are trimmed 1 3/8'' narrower than the width you order, a process that ensures smooth operation, but creates a small light gap. For this reason, we strongly recommend a full outside mount.
Room Darkening Aluminum Blinds
Room Darkening Aluminum Blinds are available in the Contempo Ultra Collection. These sleek blinds feature invisible routing holes and greater slat overlap to block the maximum amount of light when blinds are closed.
Route Holes
The small holes in standard slats that the ladder cord runs through.
S Top  
Filtered light can get through these treatments, but they cannot be seen through and provide privacy. Also called Light Filtering.
These products allow more light filtration than opaque, but more privacy than sheer.
A window covering made of material that rolls, gathers, or folds vertically up or down.
Shading Coefficient
Defines the sun control capability of the glazing system. It is expressed as the ratio of the solar heat gain through any given glazing system to the solar heat gain that would occur under the same conditions of the window under consideration were glazed with clear, unshaded, double strength window glass, designated DSA. It is utilized in the calculation of the solar heat gain and total heat gain of the glazing material or glazing system.
Solar Absorptance
The Ratio of the amount of total solar energy, which is absorbed by a glazing system to the amount of total solar energy falling on the glazing system (the portion of the solar energy which is reflected or transmitted)
Solar Reflectance
The Ratio of the amount of total solar energy, which is reflected outward by a glazing system to the amount of total solar energy falling on the glazing system.
Solar Transmittance
The ratio of the amount of total solar energy allowed to pass through a glazing system to the amount of total solar energy falling on the glazing system.
Semi-private products.
Horizontal wood or vinyl slats that may be tilted to allow some light in, or opened completely.
The individual rows of wood, pvc, or aluminum that comprise a blind.
Soft Roman Shades
A fabric shade backed with narrow horizontal rods. The rods enable the shade to form a series of tailored folds when the shade is raised. Can be ordered in a flat or teardrop style.
Soft Treatments
Window treatments that serve a primarily decorative purpose, such as draperies, cornices, valances, or swags.
Used to provide additional space between the blind and the surface it is being mounted to. Commonly used to install blinds over a raised trim. Only available with outside mount, or when mount above the window frame.
Split Stack
Vertical blinds open in the middle of the window, and stack on both sides of the window.
Spring Roller Lift
The standard lift device on roller shades. Shades are raised by pulling lightly on the bottom of the fabric, and lowered by simply pulling them down. No controls are needed.
The space that is taken up by the slats when the blinds are fully open. For vertical blinds, the stack can be on either to the right or left side or both (center open stack). If it is on the right side, the blinds will open towards the right, and vice versa. For horizontal blinds, the stack is usually on top, but can be on the bottom if the blinds are top-down (instead of raising blinds to open them, you lower the tops). Also called Stack Height.
Swivel Brackets
Hardware that allows shades to be mounted into shallow recess.
T Top  
Three-on-One Headrail
A blind with three independently operating blinds on the same headrail.
A cord, wand, or chain that controls the angle of the slats on both horizontal and vertical blinds.
See Duofold
Tubular Bottomrails
A functional and decorative element which "weights" the bottom if a blind, and enhances synchronized slat movement.
Two-on-One Headrail
A blind with two independently operating blinds on the same headrail, separated by an 1/8" between the two.
U Top  
A window covering placed under another one to create a layered look. Similar to an over-treatment.
UV Transmittance
The transmittance of the glazing/ product for the UV range of the solar spectrum. This value is used as a rating to determine the product/ glazing effectiveness in guarding against UV degradation. This value is directly related to the openness factor of the solar protection material used.
V Top  
A decorative element that is typically used to conceal the operating mechanism of a window treatment.
Valance Clip
Used to attach the valance to the window coverings.
Vertical louvers or slats on vertical blinds.
Vertical Blinds
Window coverings that have vertical slats. They can be opened from the center towards both sides, or from one side towards the other. They can also be tilted open or closed.
Visible Transmittance
The ratio of the amount of total visible solar energy which is allowed to pass through a glazing system. It is related to the amount of glare a person recieves through a glazing system.
W Top  
Wall Mount
A type of installation for vertical blinds. The headrail is mounted on the wall or trim surrounding the window or door.
The distance from one side to the other of a window. It can include the window frame or not, depending on whether it is inside or outside mount.
Wood Blinds
The slats of these blinds are made of wood or PVC. They are both long lasting and good natural insulators.