Acid-free Boston - Picture Framing Terms & Glossary

Short Glossary, Custom-made Picture Frames [48]

Acid-free Paper materials with a pH of around 7 are considered to be acid-free. These materials are less likely to harm artwork over time. Materials with a pH below 6.5 or above a pH of 8.5 are not considered acid-free.
Archival Archival framing means that all the materials involved in the process are completely acid-free. Your artwork is framed to last. An original artwork can be considered archival if no irreversible treatments (such as lamination or dry mounting) are applied, and the framing products involved are of archival quality.
Artwork Size The width and height of the artwork for which you are purchasing a frame. It is important that these measurements are accurate to 1/16th of an inch, as your frame will be custom made using these dimensions.
Aspect Ratio The relationship between the height of your photo or artwork to its length is called the aspect ratio.

Backing A semi-hard backing is placed behind the art in a frame to keep the artwork safe and prevent warping. The backing is generally a piece of foam board cut to size, and is available in white, black or acid-free (archival). The glazier points or tabs inserted into the back of the frame to keep the artwork in place will press against the backing. Order online: Board Backings
Bumper These half sphere, self-adhesive pads are placed in the bottom corners of a picture frame or canvas print to keep it from scratching or scuffing the wall when hung. Round and square foam and felt styles are also available. Order online: Bumpers

Canvas Floater A style of frame ideal for a gallery wrapped canvas print or original painting. This frame overlaps the artwork from behind (instead of in front like a traditional picture frame), where the wooden frame of the canvas is affixed to the floater frame. The floater frame surrounds the canvas, separated by a gap of approximately 1/4 inch on each side, creating a “floating” effect. Floater frames are available in a variety of styles, including “stair step”, “tapered” and “L shape”. View our large collection of canvas floater frames.
Conservation The act of preserving or protecting an artwork by taking various steps to ensure its longevity. The products used may include paper-free matboard, acid-free backing, and UV-resistant glazing and inks. Order online: Conservation Matboards Acid-free Foam Board
Conservation Framing Conservation picture framing results in an archival quality display, and ensures that whatever processes are done to the art can be reversed without damaging the original piece. It requires the use of acid-free materials (paper, backing, adhesives) and UV-protective glass or plexiglass.
Cork Boards Any material, the surface of which is covered by a layer of sheet cork. The layer may be thick or thin, and is usually backed by MDF or cardboard, sometimes with a sheet of foam between the cork and backing. Cork boards are generally used to display paper items using push pins or staples pressed into the cork surface. We offer cork board as a backing option for picture frames. Order online: Cork Board

Double Mat When mats are layered in a picture frame, the top mat forms the main border and the bottom mat shows slightly, just around the image (called the "reveal"). Double mats give an extra sense of depth to the framed piece.

Face Width The face of the picture frame (or molding) is the part of the frame you can see when standing directly in front of it while it hangs on the wall. It includes only the frame itself, not the space between the sides, nor the artwork within. The face is generally the decorated or sculpted part of the frame. The frame face width refers to the measurement from the outer edge of one side to the inner edge of the same side. It does not include the perpendicular edge (the height).
Flat Head Screwdriver A tool used for tightening and loosening slotted screws.
Floater Frame (also called a "Canvas Floater") A style of frame ideal for a gallery wrapped canvas print or original painting. This frame overlaps the artwork from behind (instead of in front like a traditional picture frame), where the wooden frame of the canvas is affixed to the floater frame. The floater frame surrounds the canvas, separated by a gap of approximately 1/4 inch on each side, creating a “floating” effect. Floater frames are available in a variety of styles, including “stair step”, “tapered” and “L shape”. Order online: Canvas Floater Frames.
Floater Metal Frames A canvas floater-style frame constructed of metal. Generally consisting of simple, modern lines and a narrow face. A canvas is secured from the back in a floater frame, while the border sits around the canvas, but does not overlap. A small gap of 1/4" is usually left between the edge of the canvas and the frame. Order online: Metal Floater Frames.
Foam Board (Same as Foam Core) A light but firm material used as the backing in framed artwork. It is constructed of a thin (approximately 1/4”) foam sheet sandwiched between layers of thick, generally glossy, paper. Prints can also be dry mounted to the foam core surface. Order online: 3/16 inch Foam Board 1/2 inch Foam Board
Frame Size Refers to the dimensions of the matted artwork that will be placed in the picture frame. For example, if the artwork is 8x10", with a 2" mat, the frame size is 12x14". The framer will automatically add an additional 1/8" to both dimensions to allow for expansion of the art over time. This additional amount is not included in the frame size.

Gallery wrap Gallery wrapping is the method of stretching an artist's canvas so that the canvas wraps around the sides of a wooden frame (called stretcher bars or strainer bars), and securing it to the back.The result is that the hardware (staples or tacks) used for securing the canvas is not visible from the front or sides.

The sides of the canvas are prepared and primed in the same manner as the face. They may be painted a solid color, or painted to continue the image appearing on the face. This method of stretching and preparing a canvas allows for a frameless presentation of the finished painting.

In canvas printing, the term “gallery wrap” refers to an image that appears on the sides of the frame as well as the front. The image on the sides is either a continuation or a reflection of the main image.

Order your gallery wrapped canvas print online today!

Glazing (1) A technique of applying oil or acrylic color in thin, transparent layers so that the color beneath shows through, modifying the color of the glaze.
(2) The clear cover placed over an artwork within a frame; this may be plastic, plexiglass or real glass.

Hardware The varying collection of screws, offset clips, wire, hooks and hangers the customer will receive with which to prepare their finished artwork for hanging, and affix it to the wall. Order online today: Framing Hardware
Hook The hook is the part of the hanging hardware that is attached to the wall, on which the artwork is hung. The most common style have a flat section which lies flush against the wall and is nailed or screwed in place. A curved lip below the nail protrudes to hold the wire or hanger that is attached to the frame/canvas. Order online: Picture Wall Hooks

Infrared Energy Light waves that can heat and therefore dry out artwork over a period of time, speeding up the decay process. Sunlight and tungsten have infrared energy. Ideally, artwork should be kept out of direct light.
Inner mat If a framed artwork has a double mat (a top mat, usually 2" wide, and a bottom mat with a reveal of approximately 1/2"), "inner mat" refers to the bottom mat, of which only a small amount is seen.
Invasive Mounting Any method of affixing artwork to another surface that cannot be undone. Once the adhesive or glue is applied, a residue from the substance will remain on the artwork. Invasive mounting methods are not conservation-grade.

L Shape Floaters A canvas floater frame style, the profile of which is an "L" shape. This type of floater frame does not have a raised step to designate the gap between frame and canvas. As a result, this frame style is generally cut 1/2" larger than the canvas to allow for the "floating" effect. Browse our full collection of .
Landscape Orientation Refers to the angle at which the framed or canvas image is hung. Landscape oriented images are those displayed lengthwise, so that the top edge (parallel to the floor) is the long dimension of the painting, and the side edge is the short dimension. Also referred to as "horizontal orientation". The opposite of "portrait orientation".
Liner A frame molding used within the outer molding/picture frame, sometimes called a "linen liner" or "insert". The may be covered with fabric, such as velvet or linen. Many liners are made from fully finished frame stock, including gold or silver. The liner serves the same purpose as a mat: to provide a distraction-free space between the art and the frame, and enhance the artwork. Liners are paired with stretched and mounted canvas prints or paintings, and do not require a clear glass or acrylic cover. A liner may also be used on large, glass-covered artwork, as the largest mat size available is 32x40". If it is more than 2 1/2 inches wide, it is called a "panel". Order online: Linen Liners

Mat A mat serves two purposes within a picture frame: first, to prevent the image from touching the glass, and second, to frame the image and enhance its visual appeal. Order online: Matboards
Mat Color Refers to the hue or shade of the mat board which will be cut to border an artwork within a picture frame. Mats are available in almost any color, though shades of white and cream are most common.
Molding The lengths of picture framing material that will be cut and shaped into a custom-size picture frame. Moldings are made from a variety of materials, including wood, metal and Styrofoam. A picture frame molding sample will usually be a corner edge piece.
Multi-Opening Mat Board Any mat into which multiple viewing windows are cut. This allows more than one picture to be showcased within a single frame. Multi-opening matted images were common in the 1980s for showing family photographs, and have begun to come back in style.
Museum matboard Another term for conservation or archival-grade matboard. To qualify, matting must be acid-free in order to prevent damage to the artwork as time wears on. Our museum core matboard is made from 100% virgin cotton rag that is bleed and fade resistant and buffered with calcium carbonite. Order online: Museum Core Matboard

Non-Glare Glass Glass where one or both surfaces have been treated chemically or mechanically to slightly roughen the surface, causing reflected incident light to be dispersed in all directions. Because the glass surface is not smooth, art images behind the glass tend to be softened. The softness depends on how far the art is from the glass. No more than two or three mats are recommended to be used with non-glare glass. If clarity is desired, objects in deep frames (shadow boxes) should not be displayed with non-glare glass.

Non-Glare Plexiglass Acrylic where one or both surfaces have been treated chemically or mechanically to slightly roughen the surface, causing reflected incident light to be dispersed in all directions, minimizing glare. Because the glass surface is not smooth, art images behind the glass tend to be softened. The softness depends on how far the art is from the glass. No more than two or three mats are recommended to be used with non-glare glass. If clarity is desired, objects in deep frames (shadow boxes) should not be displayed with non-glare glass.

Order online: Plexiglass Mounting Board or with any Picture Frame order

Offset Clips Used to affix a stretched canvas to a frame. Also known as a “Z bracket”, this stepped metal hardware has a hole in either end through which a screw or nail is driven. One end of the bracket is fastened to the stretcher bar frame, the other to the back of the picture frame. Offset clips allow for artwork that is slightly larger or smaller than the depth of the frame rabbet to be fitted. They are also used to attach a canvas to a floater frame.

Order online: Offset Clips

Plexiglass A widely accepted term for the acrylic glass often used in as the clear cover or “glazing” in framing (derived from the brand name Plexiglas). Acrylic glass is lighter than real (silicate) glass and allows for a clearer, untinted view of the artwork behind it. It does not shatter and can be treated to be archival and UV-resistant.

When you order your framed print, you can choose the best plexiglass for the display.

Portrait Orientation Refers to the angle at which the framed or canvas image is hung. Portrait oriented images are those displayed so that the top edge (parallel to the floor) is the short dimension of the painting, and the side edge is the long dimension.

Also referred to as "vertical orientation".

The opposite of "landscape orientation".

Rabbet (pronounced “rabbit”) The inner lip of a frame in which the picture framing materials, including the glass, mats, artwork, and backing, are held. Selecting a frame with an appropriate rabbet is an important part of the work of a professional framer.
Rabbet Depth The measurement of the space behind the inner lip of the picture frame, between the lip and the back of the frame. This is the amount of space available for the frame contents. Multiple mats and thick backing may require a deeper rabbet.
Reveal The visible part of a secondary mat that extends beyond the inner edge of the top/primary mat. In a double mat this is the bottom mat. In a triple mat, this refers to the middle and bottom mats.

Shadow Box A picture frame with a deep rabbet, designed for the display of three dimensional objects. Shadow box frames are available in a variety of depths from 7/8” to 2 1/4”, and should be selected based on the size of object being framed. Shadow boxes are often used to showcase sports and travel memorabilia. Order online: Custom-Made Shadow Boxes Jersey Shadow Box Frames
Single Mat Similar to a regular mat; a framed display with only one color of mat board serving as the border around the image. Unlike a regular mat, the single mat could be decorated, or have stylized corners or etching.
Standard frames A standard frame is a basic picture frame available in the sizes most common to printed images. These include 4x6", 5x7", 8x10" and 9x12". We have a wide selection of picture frames available in any size.
Stretcher bar A stretcher bar is used to construct a wooden stretcher frame used by artists to mount their canvases. They are traditionally a wooden framework support on which an artist fastens a piece of canvas. They are also used for small-scale embroidery to provide steady tension, affixing the edges of the fabric with push-pins or a staple gun before beginning to sew, and then removing it from the stretcher when the work is complete. Stretchers are usually in the shape of a rectangle, although shaped canvases are also possible. Since a stretcher is simply a frame, it can be constructed in a variety of ways. The differences in construction have to do with how the corners are built. Commercially available, pre-fabricated stretchers come in segments with interlocking corners that can be fit together like puzzle pieces. Order online: Stretcher Bars Custom-made Stretcher Bar Frames

Triple mat A picture frame display that has three overlapping mats between the glass and the image. Often, there will be a 1/4" reveal on the middle mat, and a 1/8" reveal on the bottom mat (this may be doubled in the case of a large artwork, as it is reliant on ratio). It is important to note that the rabbet of the frame (the cut out area behind the lip) must be deep enough to hold the glass, artwork, backing and three mat boards.

Turn buttons A tab with a screw hole on one end that is used to hold the artwork contents within the frame. The button is screwed into the back of the frame, close to the inner edge. The tab extends across the rabbet, keeping the backing in place. If not overtightened, the turn button can be moved off the backing, allowing the owner to easily change out the art.
Order online: Turn Buttons

UV Ultraviolet light. UV rays are beyond the visible spectrum of humans. UV radiation comes from a variety of sources, including the sun, lamps, LEDs, lasers, etc.

White core mat A mat board that is constructed from bright white fiber that is tightly pressed into a thick layer. A thinner, colored layer is laid over top to provide the color of the mat. The white core is visible in the finished display only at the bevelled inner edge.

At KeenART Media, our Peterboro White Core mats are buffered with calcium carbonate to make them stable for many years. The backing paper on the mat is conservation quality so it will not react negatively with your artwork. The white core will resist discoloration over time.

Order online:

Uncut Matboard, 32x40"

To order Custom Cut Frame MatBoards click here: Custom Cut Frame MatBoards