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 or rice 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.

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.

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.