What are conservation or preservation mats and why should I use them?

At Masterpiece Framing we offer 100% conservation/preservation mat board. 

• All materials used in a frame package of fine, historical or personally important art are preserved best by using of Conservation/Preservation quality.
• Mats are purified Alpha-cellulose (either from Rag or Purified Wood Pulp). All mats are Lignin, Alum, and Rosin free.
• Mats are buffered to a pH within the range of 7.5-9.5. The alkaline reserve should be a minimum of 5%. The Alkaline reserve should be distributed evenly in all plies.

For more information read the Library of Congress Specifications for Mat/Mounting Board.

Check out Neilsen & Bainbridge Art Care System at Nielsen Bainbridge

A little about paper mats

The standard paper mats do not protect your art.  They are non-purified wood pulp which can actually burn the paper they sit on.  The acids in the wood pulp board reacts with light and air to discolor the art.  If you have ever seen old prints that have a gold rim inside the mat-that is what wood pulp acids can do to paper.  Paper mats top colors are dyed and not pigmented.  Dyes are very light sensitve and fugative.  This means that the colors will fade significantly in short periods of time.  Next time you see a framed piece and the mat looks dull and muted compared to the art-that is fading. 

Conservation and preservation mats

These mats are either cotton rag  or wood pulp mats also, but they have had all the nasties removed from them and then they are buffered to be neutral.  The top color of these mats are also pigmented.  Pigmentation means that the actual mineral is ground and mixed with a ground to stablize and make them adhere to the surface.

from Wikipedia

A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.

Many materials selectively absorb certain wavelengths of light. Materials that humans have chosen and developed for use as pigments usually have special properties that make them ideal for coloring other materials. A pigment must have a high tinting strength relative to the materials it colors. It must be stable in solid form at ambient temperatures.

For industrial applications, as well as in the arts, permanence and stability are desirable properties. Pigments that are not permanent are called fugitive. Fugitive pigments fade over time, or with exposure to light, while some eventually blacken.

Pigments are used for coloring paint, ink, plastic, fabric, cosmetics, food and other materials. Most pigments used in manufacturing and the visual arts are dry colourants, usually ground into a fine powder. This powder is added to a vehicle (or binder), a relatively neutral or colorless material that suspends the pigment and gives the paint its adhesion.

The worldwide market for inorganic, organic and special pigments had a total volume of around 7.4 million tons in 2006. Asia has the highest rate on a quantity basis followed by Europe and North America. In 2006, a turnover of 17.6 billion US$ (13 billion Euro) was reached mostly in Europe, followed by North America and Asia.

A distinction is usually made between a pigment, which is insoluble in the vehicle (resulting in a suspension), and a dye, which either is itself a liquid or is soluble in its vehicle (resulting in a solution). The term biological pigment is used for all colored substances independent of their solubility. A colorant can be both a pigment and a dye depending on the vehicle it is used in. In some cases, a pigment can be manufactured from a dye by precipitating a soluble dye with a metallic salt. The resulting pigment is called a lake pigment.