Glossary of Picture Framing Terms

Absorbent -- This term applied to papers that absorb water solutions or other liquids. Examples of absorbent papers are blotting and toweling products. Many mat boards tend to have absorbent properties.

Acid --Is a chemical substance with a pH less than 7.0. Acids can react with paper products such as photographs causing discoloration and shortening their lifespan.

Acid Burn ----  permanent yellow or brown stain on paper art. Acid Burn occurs when artwork is framed with paper materials that are not acid-free

Acid-Free – a term that describes paper materials with a pH of around 7.0. These materials are considered acid-free and are less likely to harm artwork or discolor over time. Paper materials with a pH below 6.5 or above 8.5 are not considered acid-free for the purposes of picture framing.

Acid-Free Paper --  Are paper that has a neutral pH factor of 6.5 to 7.5 at the time of manufacture.

Acid-free paper can be produced from virtually any cellulose fiber source (cotton, wood or others) if measures are taken during manufacturing to eliminate active acid from the pulp. No matter how acid-free a paper may be immediately after manufacture, over time chemicals from processing or pollutants from the air may lead to the formation of acid in the paper. The presence of an alkaline buffer will reduce or eliminate damaging effects of these acids for the duration of the buffer's effectiveness. The most common buffering additive is calcium carbonate. Some acidic materials are chemically neutralized with the addition of alkaline products; other materials are processed to remove the acid.

Acid Migration  Is the movement of acid from an acidic material to a material of lesser or no acidity.

Acrylic- Is a clear glazing that is used as a substitute for glass in picture framing.

Adhesive – Is a bonding agent, such as glue or paste, for joining two materials.

Adhesive Release --is a chemical solvent used to remove artwork from its mounting.

Alkaline -- is a substance with a pH greater than 7.0 is considered alkaline. Alkaline substances added to acidic materials will help neutralize the acid.

Alpha Cellulose--  Is the purest form of cellulose. Cellulose is the chief consitituent of all plants. Cellulose has three chemical forms or classifications: Alpha, Beta, and Gamma. The Alpha form of cellulose has the longest, and therefore the most stable chemical chain, in turn creating the longest and strongest paper-making fibers.

Anodized –  Is the metallic surface (such as a picture frame) that has been electrolytically coated with a protective or decorative oxide. Anodizing protects the aluminum parts by making the surface much harder than natural aluminum.

Archival Components – are framing materials such as mat board, mount board and acrylic that are designed to help preserve and protect the artwork from the damage and degradation caused by acids, light and pollution. This includes components made pH neutral or slightly alkaline to help with acidity, those with UV protection to help with light.

 Artwork Size – the measured size of the actual image, not including borders or paper size. For example: you can have an image with an 8”x 10” artwork size printed on an 8.5”x 11” sheet of paper.

Backing Paper also known as a dust cover, is a liner paper adhered to the back of a frame. The back paper keeps dust and insects out of the frame package. It also helps reduce fluctuations in humidity, limits the infiltration of environmental gases, and gives your framed artwork a professional look.

Beveled Edge This is the inside edge of the mat board window is cut to a 45 degree angle. All of our mat board windows are cut with a beveled edge,(which may also cut as a reverse bevel where you do not wish to show.)

This allows about 1/16" of the core color to be visible.

Bottom-Weighting

when the bottom border of the mat board is wider than the other borders. The concept of bottom-weighting is based on the fact that the optical center (the place where a viewer's eye spends most of its time) is slightly above the true geometric center in a rectangular region.

Buffered--- Is the process where calcium carbonate or magnesium carbonate is added to mat board to make it more alkaline and therefore more likely to absorb acids and other environmental pollutants.

Buffering Agent – This is the chemical added to regulate the pH of paper. The most common buffering agent is calcium carbonate (CaCO3).

Calcium Carbonate – is used as a filler in alkaline paper-making, as coating pigment and as a buffering agent.

 Canvas Floater Frame --a type of frame used to display a gallery wrap canvas. This frame allows the entire front surface of the canvas to be visible. Any color applied to the canvas wrapping the sides of the stretcher bars will be somewhat visible in the ‘float’ space.

Canvas Transfer – a print or poster image that has been transferred and fixed to a canvas surface.

Components – a term used to describe the contents of a picture frame and includes mat board, glazing and/or mount board. For more information about picture

Conservation Framing--- a type of framing that keeps the artwork as unaltered as possible while using materials which minimize the artwork’s deterioration by environmental factors.

Conservation Grade Framing Materials--- materials such as mat board, mount board, glass and acrylic that are designed to minimize the artwork’s deterioration by environmental factors.

Conservator – a professional who specializes in the restoration and conservation of artifacts such as photographs, artwork, and documents. Conservators examine artifacts, determine their condition, suggest methods for treating them and recommend preventive conservation techniques to their owners.

Core --When you are talking about matboard is the central or innermost part; the material between the face paper and the backing paper. Less expensive paper mats may have a cream color core; some mats have a white or black core; high end rag mats have a core the same as the top and bottom.

Cotton Rag Paper-- a high-quality paper made from cotton fibers. It is primarily used for art, important documents, and money. Cotton rag paper holds pigments and inks better than wood-based papers.

Double Mat-- consists of two (2) mat boards (top and bottom). The window (opening) of the bottom mat surrounds the image. The top mat covers the bottom mat. It has a larger window, which allows a small border of the bottom mat, called the reveal, to be shown.

Dry-Mounting – the application of artwork to a substrate, such as foam core, using heat-activated adhesives in a heat press.

 Dust Cover --a liner paper adhered to the back of a frame. The dust cover keeps dust and insects out of the frame package. It also helps reduce fluctuations in humidity, limits the infiltration of environmental gases, and gives your framed artwork a professional look.

Fading – a gradual change in the color of a paper. It is usually applied to the change produced by light.

Fillet-- also called enhancers or slips, fillets are thin, decorative pieces of picture frame moulding. Fillets are often placed inside a larger frame or in between mat boards.

Finger-Jointed Wood – many picture frame mouldings are made with finger-jointed wood. Finger-jointing is a process where short lengths of timber are bonded together to produce longer lengths. Finger-jointing reduces wood waste by utilizing shorts to create a dimensionally stable and environmentally friendly product.

Float Mount-- a mounting technique where the edges of the artwork are left uncovered by a mat board. With this application the artwork appears to be floating within the frame or mat board window. Artwork can also be float-mounted on a piece of black or white foam core without a mat.

Foam Core--the board on which artwork is mounted upon inside of a picture frame. Foam core mount board is a light, but stiff material that is commonly available in white and black. Acid-free varieties are available for conservation framing.

  Gallery Wrap--a modern style of displaying art in which a canvas is stretched so that it wraps around the sides of a thick wooden frame and is secured to the back of the frame. It is suitable for displaying without a picture frame.

Gesso – traditionally a mixture of animal glue binder, chalk, and white pigment used as primer coat on wood panels, canvas, and sculpture. Modern gesso may be acrylic or soy-based and comes in a variety of colors.

Giclée – a high-quality fine art print created with an inkjet printer.

Glazing – the generic term for the glass or acrylic used to cover and protect artwork in a picture frame

Hinging --a term for adhering the components of a picture frame together including: hinging the mat board to the mount board, hinging the picture to the mat board, or hinging the picture to the mount board.

Japanese Paper --a high quality paper made from fibers of the mulberry tree. Japanese paper makes great hinges because is strong without being bulky and does not discolor or weaken with age

Landscape Orientation – a layout that is wider than it is high.

Lignin – an organic substance found in all vascular plants. Papers containing lignin give off acids as they deteriorate which can damage art.

 Matboard --a material that covers and protects the image. Mat boards have a window (also known as the exact mat opening) cut in the center through which the image can be viewed. In addition to protecting the image, mat boards are available in many different styles and colors for the purpose of enhancing artwork.

Moulding-- the material (either wood or metal) of the picture frame. Moulding can be very ornate and decorative, or it can be very simple.

 Mount Board --the board on which artwork is mounted upon inside of a picture frame. Foam core mount board is a light, but stiff material that is commonly available in white and black. Acid-free varieties are available for conservation framing.

Mounting-- the act of attaching artwork to the mat board, mount board, backer or display board. One way of mounting is by using hinging 

Multi-Opening Mat Board – a mat board with more than one window opening. Multi-opening matboards are often used for photo collage projects.

Non-Glare Acrylic --acrylic with a matte finish etched on one side to reduce glare from lighting. It is optically pure (no tint), and may cause a slight loss in sharpness. Frame Destination sells 1/10" (.098) framing grade Non-Glare acrylic. When framing with non-glare acrylic remember that the matte side goes away from the artwork.

Outgassing  --this is the release of gases from a material.

Overlap – Is a term that refers to how much of the artwork will be covered by the mat board. A standard mat window opening overlaps anywhere from 1/8" – 1/4" of the artwork.

pH Scale -- a logarithmic scale that measures how acidic or basic a substance is. The pH scale ranges from 0 (acid) to 14 (alkaline); the neutral point is 7.

Ply –This  is a layer within a mat board. High quality mat boards are manufactured in plies, dyed for color and laminated together. Mat board comes in 2-ply, 4-ply, 6-ply ,8-ply,10 -ply and now even 12-ply. Standard mat board is 4-ply and is 1/16" thick. Some mat board is not manufactured with separate plies, but will often be referred to as 4-ply to give a relative indication of the approximate thickness.

Poster –  is usually mass-produced and intended to be framed and hung as decoration. Some posters are made for special events and are limited to the demand.

Profile – When talking about frame moulding it describes the shape, height ,rabbet and contour.

Rabbet – the inner lip or groove of the picture frame, which holds the frame’s components, including the glazing, mat(s), artwork and backing.

Rabbet Depth – the height or depth of rabbet. This measurement tells you how much room you have inside for the frame’s components.

Rag Board-- matboard from non-wood products such as cotton linters, or cotton which are naturally lignin-free, stable and durable.

 Reveal-- a term used to describe the small bottom or middle mat border left visible in a double or triple mat application.

Reverse Bevel-- a reverse-bevel cut positions the bevel inside of the mat window so that it is not visible. It gives a straight edge to the mat window.

Reversibility – describes the ability to undo a framing or mounting treatment, returning the object to the condition it was in before treatment.

Riser-- the amount of distance between the top edge of the stretcher bar and the broad flat top of the stretcher bar. The riser determines how much distance you will have between the canvas and the top face of the stretcher bar.

Sawtooth Hangers – small metal bars with a serrated (sawtooth) edge that are used in place of hanging wire. Saw toothed hangers are best for lighter weight picture frames.

Shadow Box Frame – a deep frame with glass or acrylic in front traditionally used to display personal mementos such as military medals, antique jewelry, old coins, sports memorabilia and children’s toys.

Single Mat --one (1) mat whose window (opening) surrounds the image.

Spacer-- holds the artwork away from the surface of the glazing. Spacers can be made of plastic, wood, mat board or foam core.

Spray Mounting--- the application of artwork to a substrate using glues applied with aerosol sprays.

 Standard Acrylic----acrylic with no coatings, finish, or tint. It is translucent and optically pure. Frame Destination sells 1/10" (.098) framing grade acrylic.

Stretched Canvas-- a canvas that has been mounted onto a stretcher bar support framework in preparation for framing or hanging.

 Stretcher Bar Frame --a type of heavy wooden frame designed for a canvas to be wrapped and secured around it.

Stretcher Bars-- the four (4) pieces of wood material that make up a stretcher bar frame.

T-Hinge --a method for attaching artwork to the mount board. The top of the artwork is adhered while the bottom hangs free. Used when the mat board will be covering the edge of the artwork.

Tooth --a characteristic of the grain in the surface of various paper, especially drawing papers, handmade papers, and other papers of low finish. A patterned roughness in the form of minute depressions between fibers or groups of fibers on the surface. Tooth can be produced on the paper machine during forming or pressing.

Triple Mat – consists of three (3) mat boards (top, middle and bottom). The window (opening) of the bottom mat surrounds the image. The middle mat covers the bottom mat and it has a larger window which allows a small border of the bottom mat, called the reveal, to be shown. The top mat covers the middle and bottom mats and it has an even larger window which allows a small border, also called the reveal, of both lower mats to be shown.

Ultraviolet (UV) Energy – an invisible portion of the light spectrum. Ultraviolet energy fades artwork and causes paper to become yellow and/or brittle. Using ultraviolet-filtering glazing helps minimize potential UV damage to artwork. ISO 18902, the ISO standard for framing display photos, recommends using glazing that blocks at least 97% of UV energy. Frame Destination sells UV-filter acrylic and UV/Non-glare acrylic with 99% UV protection.

UV-Filter Acrylic – acrylic with a UV-filter that will block most ultraviolet radiation. It has a slight yellow tint, which may create a warming effect on the artwork. Frame Destination sells 1/10" (.098) conservation grade UV-Filter with 98% UV protection.

UV/Non-Glare Acrylic – acrylic that blocks ultraviolet radiation and has a matte finish etched on one side to reduce glare from lighting. Frame Destination sells 1/10" (.098) conservation grade UV/Non-Glare with 98% UV protection and non-glare matte surface. When framing with non-glare acrylic remember that the matte side goes away from the artwork.

V-Groove – a type of matboard cut where a thin line is cut around the top mat’s window opening. The v-groove exposes the matboard’s inner core color. It’s a purely decorative cut done for the sole purpose of generating extra focus on the artwork.

Wall Bumpers – small, felt-covered or soft rubbery plastic adhesive-backed disks that provide a cushion between the frame and the wall. Bumpers also help the frame hang flat against the wall.

Wet-Mounting-- the application of bonding artwork to a substrate, such as foam core, using wet glues and pastes with a press or weight.

Window – also known as the exact mat opening, the window is the opening cut in a mat board through which the image can be viewed. The average ready-made, retail store frame for an 8" x 10" image will have a window of 7-1/2" x 9-1/2", which allows the mat to overlap the image by 1/4" on all 4 sides. Custom frame shops will typically cut a window for an 8" x 10" image at 7-3/4" x 9-3/4" so that less of the image is covered.