Acid-Free Used to describe matting, paper or storage materials that do not contain acids that can cause discoloration or deterioration.

Acid-Free Foam Board A board made of foamed plastic (polystyrene) material sandwiched between coated paper from which the acids have been removed or have been chemically neutralized to raise the pH level above 7 (alkaline).

BEVEL Cutting or shaping the edge or end of a material to form an angle that is not a right angle, such as the bevel cut on the window edge of a mat.

BLOCKING

BOTTOM MAT - In multiple mat combinations, that mat which is nearest the art.breathing - The expansion and contraction of paper, canvas, wood, and other absorbent grounds, in response to atmospheric conditions.

BUMPER - Small self-adhesive pad, made of rubber, cork or felt, used on the bottom corners of the dust cover or back of a frame to hold the frame away from the wall at the bottom, allowing air to circulate. Also steadies the frame on the wall.

CONSERVATION (preservation) - In framing, it is the careful maintenance and protection of works of art. In conservation (preservation) framing, using materials and procedures
that will have no adverse effects on a piece of artwork and will protect the artwork from external damage.

deacidify - To chemically stabilize (make ph neutral) acidic paper.

fillet (wood) A small molding with profile that may be used as an edging on a mat or frame lip. Profiles may differ somewhat. May also be called a slip.

fit(ting) The process of assembling glass, mats, artwork and filler board into a picture frame, including the addition of a dust cover, hangers and bumper pads.

float(ing) A means of securing artwork to a rigid support so all edges are visible.float mat A window mat raised or elevated off the underneath surface by spacers.

floater A molding designed to give the artwork the appearance of floating within the frame. Floater frames have a rabbet in reverse; the artwork is fitted in from the front.

FRAME That decorative or functional element which surrounds an item, providing protection and display functions. Typically made of wood or metal, a frame generally provides the architectural support element for a work of art.

frame design 1) The characteristic appearance of a frame, identified with a historical period or as being that of a particular frame maker. 2) The process whereby the appearance of a frame is planned, designed and executed. 3) The process whereby framing components are selected for a particular artwork.

Gilding Covering a surface with gold leaf.

hinge A small piece of paper or tape generally used to attach paper art to a mounting board.

JAPANESE PAPER - Handmade paper with a web of strong naturally formed fibers; ideal for hinging purposes. The best are made with 100 percent kozo or gampi fibers, which have not been bleached or chemically processed.

join(ing) In framing, the operation of gluing and nailing the corners of a frame.

LEAFED A frame or object that has had gold, silver or metal leaf applied to it.

lift mat To raise or elevate the window mat off the artwork by means of spacers made of mat board or foam board strips attached to the mounting board or the underside of the mat and not visible.

liner 1) A frame molding used within the outer molding. May be covered with fabric, often velvet or linen. Many liners are made from fully finished frame stock, including gold or silver. Sometimes called an insert. If over 2 1/2 inches wide, called a panel. 2) Inner mats and fillets are also called liners.

MOLDING - Wood or metal which has been refined and shaped and which includes a rabbet for use in the framing industry as frame stock.

Mount - To secure a work of art to a supportive object or setting for display or study.mounting board A surface, substrate or secondary support to which any art or object is attached.

oval frame A frame with an elliptical shape.oval mat A mat with an elliptical opening; may have an oval or rectangular perimeter.

oversize Describes the size of a frame or materials that are larger than standard 32- by 40-inch mat board.

picture frame A structure, usually of wood or metal in which a painting, print or other object is enclosed to improve or enhance its appearance, to isolate it from a wall or to link it to a decor, as well as to support and protect it.

picture hanger A device attached to the wall on which the frame is hung or attached to the molding of a frame by which the picture is hung.

Rag Board Matboard Made form 100% cotton, 100% acid-free, used in museum mounting and framing. (At one time, rag board was actually made from cotton rags).

scoop A common frame molding shape, a cross section showing a concave or hollowed profile.

screw eye A screw with a head shaped into a loop to which the hanging wire on the back of a picture frame is attached.

security hanger A type of hanger with one section attached to the back of the frame and the other to the wall. When positioned together, the frame is held securely and requires a special tool to separate the hanger parts.

shadow box A frame made from a deep molding in which three-dimensional objects may be displayed.

spacer(s) -

united inch In framing, the combined inches of one length and one width of a frame; e.g., an 8x10 frame is 18 united inches.

UV filtering acrylic sheet A glazing material consisting of an acrylic sheet which has been formulated to remove the damaging ultraviolet rays from light.

Museum Mount, or Museum Framing The safest method of hinging, matting and framing artwork that utilizes only acid-free materials.Acid-free
Technically, material having a pH of 7 or higher are considered to be acid-free. Acids are evil as far as framers are concerned. Cardboard, for instance has a very high acid content, making it unsuitable for conservation framing, or any framing really. Acids cause papers to become stained and brittle over time.
Some regular matboards claim to have acid-free core and backing paper. Making it completely free of acid, right? Well, no. While this is better than nothing, the boards still contain lignin which down the road results in a more acidic board. These regular boards are buffered with calcium carbonate to neutralize the existing acids, but this buffer will be overwhelmed as time goes on. Also keep in mind that the surface paper is not acid-free and outgasses pollutants, and dyes are used for coloring the surface which fade quickly compared to pigments.
Conservation-grade boards are completely acid-free in the commonly thought of sense of the word.Alpha Cellulose
This is plant (usually wood) pulp that has been purified, removing lignin and other potentially damaging substances, leaving an almost pure cellulose which is of a neutral pH.Alphamat
Alphamat is a brand name for a conservation matboard made by Nielsen & Bainbridge. It is composed of alpha cellulose, the surface paper is colored using light-fast pigments, and the board is part of the Artcare family of products utilizing MicroChamber Technology.

Alum
This is a chemical that is sometimes used to set dyes and sizings (adhesives) in papermaking. Alum is not an archival substance and is acidic. None of the conservation matboards or conservation materials include alum.

Archival
As a matter of convention, the term archival with regard to framing is generally considered synonymous with conservation or preservation framing. If something is done employing archival methods, it's done in such a way that the art piece is preserved in the best possible manner, or at least in a manner appropriate for an archive—a storage facility for items meant to be preserved. One could argue that there is no such thing as archival framing as a true archive would not put something on display, but store it away in a safe container away from potentially damaging light.

Artcare
Artcare is a trademark of Artcare (UK) Limited, used under license by Nielsen & Bainbridge, LLC. See MicroChamber Technology.

Buffer - A buffering agent is a substance added to a paper product to either help neutralize existing acids or to help maintain an alkaline pH over time. After a number of years, due to external pollutants, a truly archival board can become acidic even though it contains nothing internally to cause acid formation, buffers help to delay the board reaching an acidic pH level. Two common acid-neutralizing buffers are calcium carbonate and magnesium carbonate. The buffer creates what is also sometimes called an Alkaline Reserve, that is the amount above what is required to create a neutral pH condition in the paper. It's interesting to note that some rare photographs react poorly to alkalinity of the buffers and are best framed using unbuffered pH neutral boards.

Calcium Carbonate
See Buffer.

Cockling - This just means buckling or waving of an unflat art piece.

Conservation Framing
Conservation framing is preparing an item for display in a manner that preserves the item, keeping it as unaltered as possible while protecting it from degradation. Ideally, anything done to a piece of artwork should be completely reversible, allowing the artwork to return to it's original condition as is it had never been framed.

Conservator
A conservator is an individual who specializes in the care and treatment of artwork, such as restoration or repair of damaged artwork. Conservators go through years of training and apprenticeship.
Framers are not, as a general rule, conservators. It's the old story of "trying to serve two masters." While some framers may be quite knowledgeable in the handling of artwork, before using a framer claiming to be a conservator or who is willing to take on repair of valuable artwork, I recommend first checking with full-time conservators for references on the framer.
Also I, personally, would not let a conservator do my framing. Unfortunately, some of the most poorly cut mats are found in museums having been cut by conservators.
On a side note, by the same reasoning I would not let a photographer frame my photos.

Foxing - Foxing is simply the small medium-brown spots you commonly see on very old paper. These are growths on the paper as a result of moisture and warmth. These can be bleached out by a conservator, though many conservators recommend to let them be. You can help reduce the risk of foxing, which can develop even on new artwork, by hanging your artwork in an environment devoid of high humidity. This can be difficult when your home doesn't get much sunlight. If you get mildew easily in a certain area of your house, avoid hanging valuable pictures there.

Hinges
A hinge is a paper or cloth product used to secure a piece of artwork in place. The easiest to reverse are made of Japanese tissue paper and are adhered with wheat starch paste—these are difficult for inexperienced people to do on most paper artwork due to fact that the introduction moisture can result in cockling artwork where the hinges are located, especially on thinner papers. Hinges should be water-reversible and pH neutral. Ideally, hinges should be weaker than the artwork, the idea being that if the framing package is dropped then hinges will tear first—not the artwork. Masking tape is about the worst tape you can use for hinging, scotch tape, duct tape and packaging tapes aren't far behind.

Lightfast
A paper that resists fading is considered to be lightfast. Papers are colored using dyes or pigments. Dyes are not lightfast, however most pigments are less fugitive than dyes and better maintain their original color. When exposed to light the color red gradually changes to pink. How fast this transition occurs depends on how resistant the dye or pigment is to fading. But just about everything fades, it's just a matter of time and exposure.

Lignin
This is a naturally occurring part of wood pulp that is wonderful for the creation of acids. Hence, this is bad for framing and you'd like any paper products to be lignin-free. Cotton (sometimes called rag board is naturally so, and alpha-cellulose is also lignin-free.

Magnesium Carbonate
See Buffer.

MicroChamber Technology
Zeolites are little molecular traps (microchambers) that capture airborne pollutants and turn them into an inert substance. When manufactured into matboards, gasses that are released by aging wood frames or other acidic materials will not be floating free to harm artwork. The Artcare line of products made by Nielsen & Bainbridge incorporate this technology.

Outgas
As materials age, they release gasses, usually harmful. This process is called outgassing. These outgassed pollutants contribute to an accelerated breaking down of the materials around it. The effects of outgassing can be reduced by utilizing a board incorporating MicroChamber Technology, such as Alphamat.

pH Neutral
The pH scale is used to indicate the acidity or alkalinity a particular item. A pH of 7.0 is in the exact center of the scale and is considered neutral. A lower pH of 6, for instance, is acidic. A higher pH such as 8 is alkaline and is not as damaging to artwork—however, a very high pH can cause problems too. Most conservation matboards are buffered to a pH of about 8.5. This amount above 7.0 is called a reserve.

Preservation
See Conservation.

Rag Board
This is actually an antiquated term still used as a convention. 100% cotton boards at one point were made from old rags. These days museum boards are made from cotton linters, which are the fibers left on the cotton seed after it has been run through a cotton gin. The fibers are actually still too long to use at this point and are actually shortened before the board is made. The cotton fibers are still relatively long compared to other types of fibers and result in a durable, though relatively soft, board.

RagMat
RagMat is a brand name for a conservation matboard made by Crescent. It is composed of cotton, the surface paper is colored using light-fast pigments.

Reserve
Buffers are used to create what is called an Alkaline Reserve, that is the amount above (or in "reserve") what is required to create a neutral pH condition in the paper.Zeolites
See MicroChamber Technology.
Quality Check
Many people have no idea how to tell a well framed picture from a poorly framed picture—aside from the obvious: color selections and the condition of your artwork. So here's how to become an expert.

MattingCorners A well cut mat will have a very clean cut opening where the bevel meets in the corner exactly, not short (resulting in a fuzzy appearance) or too long, known as an "overcut." Also the opening should not flare out or in near the corner, known as a "hook."Correct Matboard The mat should be cut out of the board you specified and not substituted without your knowledge. There are two things to know however. One, the glazing will alter the appearance of the board—glass will tint the board green a small amount, acrylic merely makes the board look ever so slightly darker. Two, there can be small variations in the color of the board due to the manufacturer, but significant differences are quite rare.Clean Bevels The bevel of the mat should be free of specks. Sometimes the boards are manufactured with bits of hard material in the core that are exposed on the bevel when the board is cut. These should be removed if they are very small or the mat simply should be recut.FramesCorners The most problematic part of a frame is the corners. These should meet flush without gaps, the top surface of the moulding should be level across the corner from one side of the frame to the adjacent side. For wood frames, small (not obvious) amounts of correctly matched putty are usually used to make sure there are no gaps in the corner.Finish Also the sides of the frames should match in color and shape. A certain amount of color variation is expected with natural wood stained finishes where the grain is showing, depending from which part of the tree a particular "stick" of frame moulding was created. This doesn't mean the frame should have knots or an inconsistent finish. The frame also should not have any blemishes.Securing The best quality wood frames should have no holes from nails visible from the sides of the frame (except on tall thin frames where they are actually required). We use an underpinner which drives V-shaped metal wedges into the back of the frame to compliment glue in holding the frame together. Some shops use plastic wedges to hold routed corners, but its hard to achieve a properly aligned corner with this process, in our opinion.

GlazingPerfectly Clear The glass (or acrylic) should be free of ALL scratches and blemishes, including small bubbles in the materials. Looking close you should find none. This is not always easy, but it makes a difference.We called up to complain one time to a glass distributor about a particular manufacturer's glass products having defects, and they said we were the only one to complain. The customer service representative said, "I know where I'm bringing my framing!"Styrene should not be used in framing, it yellows and shows hairline fractures as it ages. This plastic product is sometimes seen in premade frames and in discount frame shops.SpacersOne Piece Spacers The plastic spacers to separate the artwork from the glass, if used, should be a single piece under the lip of the frame. Some shops cut corners and splice short pieces together so they have less waste, but this results in unsightly miters that you can see when viewing at the proper angle. (However, the strips are universally manufactured in only five foot lengths—this has to do with UPS regulations . . . don't ask—so if your order is over 60" long, splicing is necessary.)Assembly/FittingFlaw Free The glazing should be free of all streaks, there should be no specks or hairs trapped under the glazing. The matting should be free of smudges.Sealed We seal our metal frames with a durable cloth tape, something pioneered in our shop over 20 years ago. Almost no frameshops do this and if someone else is doing it, they more than likely learned it from us. Wood frames should be paper or tape sealed on the back. (In the United States, paper is the norm, in Europe tape is common.) The wire on the back should be wrapped tightly and neatly and there should be equal amounts of wrapped wire at each end.No Gaps Depending on how you specified the artwork be held in place it may be perfectly flat or it may have a certain wave to it. (See Picture Framing FAQs.) There should not be gaps under the mat around the artwork, it should be snug (unless the artwork itself is very wavy). The backing board has to be put in the correct way to assure this.The Things You Can't SeeUnfortunately, once the order is complete, there are things you can't see—until later—that also determine how well your job was done.Securing Artwork Valuable pictures secured by hinging should be only hinged at the top, not secured with tape all around, as this causes buckling. Also proper materials should be used for hinging. Masking tape is the evil-of-evils for hingings, as rubber cement is the evil-of-evils for mounting. If a shop vacuum-mounted your valuable artwork without your knowledge in order to "please you" by making it flat, you'll probably see some yellowing in few years down the road, not to mention a lesser appraised value to the mounting.

Backing/Substrate The backing board should be a single piece, not spliced, except when absolutely required. (We've especially seen this when redoing some shops' somewhat oversized orders, where they "cut corners.") Cardboard and wood products such as masonite should not be used in your order anywhere since these are highly acidic and even with "barriers" can still affect the artwork.Okay, so there you go. A crash course in what to look for in your framing orders. If you want to see poorly executed framing, shop around (or even scrutinize most museums' matting) then come to us for the good stuff.
Examples of Bad Corners Hook
Line indicates where the bevel should have been.
Corner Tear
Opening was undercut then pulled out.
Overcut
Blade didn't stop as soon as it was supposed