Guidelines Concerning Art on Paper

Matting was originally developed as a method of protecting artwork by isolat­ing  the surface of the artwork from the surface of the glass, as well as away from  the edge of the wood frame.

This is important because the glass tends to condense moisture and provide an  ideal environment for mold to grow on the surface of the artwork. Also, wood  becomes increasingly acidic over a period of time and acid migration can occur  to the artwork. It was some time after its functional invention that the  decorative qualities of matting seemed to overcome the original purpose. If a  mat is consid­ered undesirable for whatever reason, some means of separating the  surface of the artwork from the surface of the glass is still necessary. Setting  the artwork back away from the glass can be accomplished by using a wood or  plastic spacer of approximately 1/4 inch along the frame between the backing and  the glass.

In  setback framing, I mount the backing board to the support board, because I have  seen too many backing boards creep out from the edge of the setback material.  This happens because of mishandling or the natural expansion and con-traction  that these boards may undergo with changes in humidity. Particularly with  setback framing, contemporary galleries often frame with wooden support bars  built into the back of the picture frame for added strength.

Cross Section of Framing with a Mat

 Cross Section of Framing with a Setback




This is often necessary for frames that are  large and/or will be handled a great deal. Support bars are a particularly good  idea when glazing with clear acrylic sheeting in larger sizes because plastic  sheeting tends to bow and can pop out of a picture frame.

The following rules apply to most paper, fabric, and any work that needs to be  protected from the atmosphere and mechanical abuse.

1. Never mount permanently any valuable or  potentially valuable artwork, unless  the artwork requires the support, such as a collage or a piece of artwork that  cannot support its own weight. If it cannot be held in two places without risk  of tearing or distortion, it should be considered for mounting. If you do choose  to mount, you should regard the artwork and the mounting board as one piece  permanently.

The definition of conservation mounting seems to be undergoing some revi­sion.  The old definition is that the adhesive should be pH neutral, water reversible,  and of vegetable origin. The original reason behind the use of vegetable-based  adhesive was that other pastes were of animal origin and tended to become acidic  as they aged as well as less reversible with water. The pH neutrality is  important because acidity breaks down cellulose and weakens the paper. If there  are lignins (the natural glues that hold plant cells together) still present in  the paper, the paper will turn brown. Acidity can also affect many dyes and  pig­ments dramatically by changing their colors. Recent studies show that an  adhesive may appear to be pH neutral to start with, but that there are no  guaran­tees it will remain so over many years. Reversibility with water was  important to conservators because the adhesive could easily be washed out  without damaging the artwork. Today, however, a large variety of materials may  be used to pro-duce a piece of artwork. There are many pieces that would be  destroyed or seriously altered if washed in water but would not be if washed in  other solvents. Finally, there are now chemical adhesives that indicate the  possibility of aging characteristics equivalent to vegetable-origin adhesives.

So, you may ask, “What do I do?” If you must mount the picture, decide which  will affect your artwork the least—water or organic solvents. Watercolors, for  example, would be affected less by organic solvents, while etchings would be  less affected by water, if removal of the artwork from the support became  necessary in the future. Select an adhesive that has a good record for  nonyellowing and for maintaining pH neutrality over time, and that will be least  harmful to your artwork if you have to remove it.

2.               Never use pressure sensitive  tapes, such as masking, drafting, magic, sur­gical, and packing tapes. All these tapes will self-destruct and  severely damage artwork wherever it is touched by the tape. There are currently  only two excep­tions to this rule—tapes produced under the name Filmoplast by  Hans Neschen GmbH & Company in Germany and Archival Aids Document Repair Tape  made by Ademco Products in England.

3.               Never secure artwork in more  than two places. Exceptions to this  rule should be made only with extremely wide pieces and with the understanding  that for every additional place the artwork is secured you risk having twice the  number of ripples. This is because the natural expansion and contraction of  paper from variations in temperature and humidity will be restricted.  Recom­mended methods for securing artwork will be discussed later.

4.               Never use any ground-wood  pulp-board or paper, chipboard, or cardboard as backing or storage for artwork. These boards, especially corrugated  card-board and chipboard, are highly acidic, contain iron and copper, and have  been known to damage artwork, even without direct contact. The acids can even  bleed through four-ply museum boards.

5.               Never use conventional wood  pulp boards for matting or backing of original or valuable artwork. Instead, use  museum or conservation boards. Unless  the boards are of 100 percent rag or are of lignin-free alpha wood pulp that has  been buffered to remain acid-free, they will damage the artwork. Such damage can  be seem as soon as six months, and may in some cases be irreversible. Pulp  boards may be used only if they are not in direct contact with the artwork and  are separated by a four-ply museum or conservation board. With matting, the edge  of museum board should extend at least 1/4 inch past the edge of the wood-pulp  board to prevent any acids in the wood-pulp board from cascading over the edge  of the museum board.

 Cross Section of Framing with a Strainer





6.               Never use single-strength glass  larger than 36″ x 48″. If you have not already guessed the reasoning behind this rule,  you should first consult an insur­ance agent regarding the extent of your  insurance coverage.

7.               Never glaze with acrylic  sheeting for artwork done in charcoals and/or pastels. Plastic sheeting can develop a powerful static  electrical charge and can lift a significant amount of material off the paper on  to the plastic surface. You should also be aware of the fire hazards of plastic  sheeting and its ability to give off poisonous gases when burning with  insufficient oxygen.

8.               Never put original or valuable  artwork, especially glossy photographs and acrylic paintings, in direct contact  with the glass in a picture frame. Glass tends to collect moisture on its surface, and when it comes in contact  with the surface of paper artwork it can provide an ideal environment for the  growth of mold. Foxing, which is the appearance of small brown spots on artwork,  is most often attributed to mold. However, foxing can also be caused by iron  deposits in reprocessed wood-pulp backing boards. Photographs and acrylic  paints, primarily due to the nature of their surface films, tend to adhere to  glass over a period of time and the surface of the artwork can be damaged if the  picture has to be removed.

9.               Never allow the edges of a  piece of artwork to touch the edge of a wood frame. Wood has lignin, which breaks down and becomes  acidic. Moreover, many woods, such as oak, are naturally highly acidic. The  artwork should be at least     inch away from the edge of the wood.

10.           Never cut, trim, or in any way  alter an original piece of artwork without the clear consent of the owner. In California, it is a violation of  the law even for the owner to alter a recognized piece of artwork without the  consent of the artist! California passed the Art Preservation Act of 1979, which  was amended in 1982 and became the model for similar acts in New York and  Massachusetts. The law provides for actual and punitive damages as well as  attorneys’ fees for willful disfigurement or destruction of fine artwork.

11.           Leave restoration to a  recognized professional restorer. Most professional restorers spend a great deal of their time correcting the work  of self-appointed amateurs.

(Excerpt from ART HARDWARE: The Definitive Guide to  Artists’ Materials, by Steven Saitzyk © 1987)