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Picture Framing Glossary

Tools, Tricks & Terms of the Picture Framing Industry




Term applied to papers that absorb water solutions or other liquids. Examples of absorbent papers are blotting & toweling products. Many mat boards tend to have absorbent properties.


A chemical substance with a pH less than 7.0.  Acids can react with paper products such as photographs causing discoloration & shortening their lifespan.

Acid Burn

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

Acid Etched

In glazing & decorative work, acid etching alters one or both sides of the glass sheet to change its reflective qualities. When the etching is completed, all acids are neutralized & the surfaces are cleaned.


A term that describes paper materials with a pH of around 7.0.  These materials are considered acid-free & 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

Paper manufactured such that active acids are not included or are eliminated.  A 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

The movement of acid from an acidic material to a material of lesser or no acidity.


A clear, industrial plastic used as a substitute for glass in picture framing.


Trade name for high quality conservation grade acrylic glazing.


A bonding agent, such as glue or paste, for joining two materials.

Adhesive Coated Boards

A board with an adhesive coating on one side that may be neat-activated or pressure sensitive.

Adhesive Release

A chemical solvent used to remove artwork from its mounting.


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

Alkaline Paper

Paper manufactured with sheet alkalinity, most commonly associated with the presence of calcium carbonate filler.

Alpha Cellulose

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 & therefore the most stable chemical chain, in turn creating the longest & strongest paper-making fibers.


A 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.


An acronym for the American National Standards Institute.

Archival Components

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

Artwork Sandwich

The stack of components, ex. mat board, backer board & glazing.


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.



An acronym for the American Society for Testing & Materials.

ATG Tape

A name brand for adhesive transfer tape, similar to double-sided tape but it is adhesive, sticky on both sides, without the tape.  ATG actually means Adhesive Tape Gun & ATG tape is dispensed from the Adhesive Tape Gun.  Used for photos, framing, matting, crafts & scrapbooking.

Back Paper

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

Beveled Edge

When the inside edge of the mat board window is cut to a 45 degree angle.  This allows about 1/16" of the core color to be visible.  Also used as a Wood-Mounting edge treatment for contemporary display of wall art.



To give up color when in contact with water or a solvent.  Undesired movement of materials to the surface or into an adjacent material.


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.



A process where calcium carbonate or magnesium carbonate is added to mat board to make it more alkaline & therefore more likely to absorb acids & other environmental pollutants.

Calcium Carbonate

Calcium carbonate is used as a filler in alkaline paper-making, as coating pigment & as a buffering agent to regulate the pH of paper.

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 & fixed to a canvas surface.


A genre of art in which the urban environment is the principal subject.  Cityscapes, the urban equivalents of landscapes, include street scenes & skylines.


A term used to describe the contents of a picture frame & includes mat board, glazing &/or mount board. 

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 & acrylic that are designed to minimize the artwork’s deterioration by environmental factors.


A professional who specializes in the restoration & conservation of artifacts such as photographs, artwork & documents.  Conservators examine artifacts, determine their condition, suggest methods for treating them & recommend preventive conservation techniques.


In matboard, the central or innermost part; the material between the face paper & 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 & bottom.

Cotton Rag Paper

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


Tiny, hair-like cracks on the surface of an acrylic sheet resulting from high internal stress.  The effect results from chemical exposure in combination with mechanical forces or impact.


Double Mat

Consists of 2 mat boards (top & 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 adhesives in a vacuum press.

Dust Cover

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




Items, normally made of paper, created for a specific, limited purpose.  Some examples of ephemera include advertisements, tickets, brochures & receipts.  People often collect ephemera because of their association with a person, place, event or subject.


In matting the ability of a surface to withstand the removal of light pencil lines with a rubber or gum eraser.



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


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 & environmentally friendly product.

Flat File

A cabinet specifically designed for flat items such as drawings, prints, maps & large documents.


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.


Floater Frame

See Canvas Floater Frame

Foam Core

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

Frame Size

See Picture Frame Size


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 & is secured to the back of the frame.  It is suitable for displaying without a picture frame, or can be mounted in a Canvas Floater Frame.

Gatorfoam or Gator Board

A heavy-duty, extruded polystyrene foam board bonded between two layers of Luxcell wood-fiber veneer.  Also known as Gatorboard, Gatorfoam comes in sizes ranging from 3/16" -  2" thick.


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


A high-quality fine art print created with an inkjet printer.


Bright & dazzling reflected light.


A type of glazing used in picture framing.  Glass is commonly composed of sodium carbonate, lime & silica (sand).


The generic term for the glass or acrylic used to cover & protect artwork in a picture frame.  Posters On Board trusts Tru Vue Glass & Acrylic for all framing solutions.


Adhesive of animal origin, composed of complex protein structures.  The terms, "glue" & "adhesive" are used interchangeably & may also include petrochemical adhesives.

Gnat's Ass

Very small measurement used by toolmakers,  engineers & picture framers, or roughly 1/10,000th of an inch.  Actual size may vary between shops.  Also considered a fraction of a skosh which is equal to about one nudge of a dial. 

Hanging Kit

Contains the components necessary to hang an assembled picture frame.  A wood frame hanging kit will contain screw hole hangers with screws, hanging wire and protective wall bumpers.  A metal frame hanging kit will contain omni hangers for attaching the wire to the frame, hanging wire & protective wall bumpers.


The hangers, brackets, screw eyes & other materials used to assemble a picture frame.



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.  Also called T-Hinges & V-Hinges.

Infrared Energy

Is located below the color red on the light spectrum.  Infrared energy exists in sunlight & tungsten.  It heats artwork, which can dry it out prematurely & accelerate decay.  Keeping artwork out of direct light in cooler areas can help reduce damage from infrared energy.

Invasive Mounting

Saturates the art during bonding & residue will still remain after removal.   Examples of invasive mounting techniques are spray adhesives & commercial wet glues.

Japanese Paper

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


A genre of art in which the natural outdoor environment is the main subject, using natural features as the basis of the composition.

Landscape Orientation

A layout that is wider than it is high.


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


A textile made from the fibers of the flax plant, Linum usitatissimum.  Linen fabric is one of the preferred traditional supports for oil painting, it is preferred to cotton for its strength, durability & archival integrity.

Mat Board

A material that covers & 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 & colors for the purpose of enhancing artwork.


Microfiber is used to make non-woven, woven & knitted textiles, such as Norwex Microfiber Smooth Towel & Microfiber Terry Cloth.  The shape, size & combinations of synthetic fibers are selected for specific characteristics, including: softness, durability, absorption, wicking abilities, water repellency, electrodynamics & filtering capabilities.


The material (either wood or metal) of the picture frame.  Moulding can be very ornate & 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 & black.  Acid-free varieties are available for conservation framing.


Attaching artwork to a Wood Board,  Mat board, Mount Board, Backer or Display board.  One way of mounting is by using hinging.  See also Dry Mounting, Pressure Sensitive Mounting & Wet Mounting.

Multi-Opening Mat Board

A mat board with more than one window opening.  Multi-opening mat boards 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) & may cause a slight loss in sharpness.  We offer UV framing grade Non-Glare acrylic.  When framing with non-glare acrylic, the matte side goes away from the artwork.

Non-Invasive Mounting

Means the bonding technique remains totally reversible allowing the art to be returned to its original state without any adhesive residue remaining upon removal.  Examples of non-invasive mounting techniques are: hinges, edge strips, natural starch & corner pockets.

Optical Brightening Agent (OBA)


A dye that absorbs light in the ultraviolet & violet region of the electromagnetic spectrum.  OBAs are used in many papers, especially high brightness papers, resulting in their strongly fluorescent appearance under UV illumination.



The release of gases from a material.


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.


A picture that depicts a wide, horizontal view, particularly a landscape.  Panoramas are significantly longer in the horizontal dimension than the vertical dimension.

Pantone Color Guide

A standardized color matching system used by artists, designers, printers, manufacturers, marketers & clients in all industries worldwide for accurate color identification, design specification, quality control & communication.


A material made of cellulose pulp, derived mainly from wood, rags & certain grasses, processed into flexible sheets or rolls by deposit from an aqueous suspension & used chiefly for writing, printing & drawing.

pH Scale

A logarithmic scale that measures acidity.  The pH scale ranges from 0 (acid) to 14 (alkaline); the neutral point is 7.

Photo Activity Test (PAT)


An international standard that evaluates photo storage & display products.  For more information about the PAT, visit the Image Permanence Institute.


Picture Frame

Provides an attractive border & functions as a structural support for the artwork.


Picture Frame Size

Also called "allowance," this refers to the size of matted/mounted artwork.  Framers will cut the picture frame moulding approximately 1/16" – 1/8" larger to accommodate the matted/mounted artwork & the glazing.

Plein Air Picture Frame

A plein air frame is usually a wide flat moulding with a raised & rounded top edge.  Plein air frames are ideal for canvas art.


A brand of conservation grade acrylic glazing.


A ply (plural - plies) is a layer within a mat board.  High quality mat boards are manufactured in plies, dyed for color & laminated together.  Mat board comes in 2-ply, 4-ply, 6-ply & 8-ply.  Standard mat board is 4-ply & 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 approximation of thickness.

Point Driver

A hand-held device that fires points into a picture frame.  To operate, press the nose of point driver against the rabbet & squeeze the handle.  For the most accuracy, make sure the bottom of the point driver is flat against the surface of your table.


Point Squeezer

A vicing tool that squeezes the point into the rabbet.  Point squeezers have an adjustable magnetic anvil that holds the point in place while squeezing.  The opposing jaw is fitted over the frame, then the handle is squeezed, closing the jaws and pressing the point into the rabbet.  This is also known as a Frame Fitting Tool.


Thin metal tabs used to hold the mat, mount board and/or glazing inside of wood picture frames.  Some points are stiff while others are flexible to allow access into the frame.


A depiction of an individual's likeness.  Portrait styles include: head & shoulders, bust, three-quarters & full-length.

Portrait Orientation

A layout that is taller than it is wide.



A printed illustration that is usually mass-produced & intended to be framed & hung as decoration.  Posters On Board, in the Minneapolis area, offers the largest selection of Posters in the Midwest.

Pressure-Sensitive Mounting

The application of bonding artwork to a substrate, such as foam core, using an adhesive that activates when pressure is applied.

Print Size

See Artwork Size.


A term describing how picture frame moulding looks when viewed from one end.  A moulding’s profile includes its height, width, contour & rabbet.


The inner lip or groove of the picture frame, which holds the frame’s components, including the glazing, mat(s), artwork & 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 & durable.  A common rag board is Bainbridge AlphaRag Mat Board.



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.


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


The amount of distance between the top edge of the stretcher bar & the broad flat top of the stretcher bar.  The riser determines how much distance you will have between the canvas & 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.  Sawtoothed hangers are best for lighter weight picture frames.

Screw Eyes

Screws with a loop at the end.  They are used to attach hanging wire to the back of a wooden picture frame.


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, jerseys, sports memorabilia & children’s toys.


Single Mat

One (1) mat whose window opening surrounds the image.



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 & secured around it.

Stretcher Bars

The 4 legs of wood material that make up a stretcher bar frame.


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.


A characteristic of the grain in the surface of various paper, especially drawing papers, handmade papers & other papers of low finish.  A patterned roughness in the form of small 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 3 mat boards (top, middle & bottom).  The window (opening) of the bottom mat surrounds the image.  The middle 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.  The top mat covers the middle & bottom mats & 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 & causes paper to become yellow &/or brittle.  Using ultraviolet-filtering glazing helps minimize potential UV damage to artwork.  The standard for framing display photos blocks at least 97% of UV energy.  We offer UV-filter acrylic & 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.  We sell 1/10" (.098) conservation grade UV-Filter with 98% UV protection.

UV/Non-Glare Acrylic

Acrylic that blocks ultraviolet radiation & 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 & non-glare matte surface. When framing with non-glare acrylic, the matte side goes away from the artwork.


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.


A method for attaching artwork to the mount board.  Similar to the T-hinge except it is used when the mat board will not be covering the edge of the artwork.


A term that refers to a mat board with a smooth, texture-free surface.

Wall Bumpers

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

Wet Mounting

The application of bonding artwork to a substrate, such as Fiber Board or Foam Core, using wet glues & with a vacuum press or weight.

Wood Mounting

A special process where flat art is permanently adhered to a fiber board as a contemporary wall display method without the need for a traditional frame.  Commonly wood mounted items are:  Posters, Art Prints, Diplomas, Certificates, Photographs, Kids' Art, letters, Book Covers, Program Covers, Sheet Music, Brochures, Menus, Maps, Greeting Cards, Cartoons, Drawings, Labels, Caricatures, Chalk Drawings, Newspaper & Magazine Articles, Calendar Pages, Puzzles... Just about anything on paper!  See


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.


Aluminosilicate substances added to mat board that help it absorb harmful environmental pollutants.

Print Size to Artwork Size

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