A Word to the Wise or Else Caring for Works on Paper By Halima Taha
ART COLLECTORS ARE BETTER AT WANTING than at having. They often exert tremendous energy in a diligent search for the best piece of art they can afford. Then, having acquired their treasures, they think the process is complete. The mistake that is often made is ignoring the value of caring for their new acquisition once they have brought it home. If you are among those who ignore the value of caring for your art work, you risk the possibility of losing it to something more criminal than theft - carelessness which is within your control to prevent.
Works of art on paper include a broad range of styles and mediums ranging from Old Master prints to fluorescent silk-screens to monetarily worthies, but sentimentally priceless children's scribbles. For the purpose of this article, works of art on paper include one-of-a-kind originals like pencil, charcoal chalk, watercolors, collages, gouache and pastel drawings. They also include multiple original prints, like lithographs, silk-screens (serigraphs), engravings, etchings, dry point, mezzotints, aquatints, wood cuts; and a host of other artistic creations that are made in man% different ways. The primary factor that all of these works of art have in common is the paper on which or of which, their images are composed.
Although the history of papermaking is fascinating and can be traced to 2nd century China spreading westward along the trade routes to Korea, Japan, Nepal And India during the 8th century and a century earlier to the Arab world via North Africa with Moorish influences, with its last stop in Europe - our concern is the relationship between the various chemical reactions to paper and their conservation.
This article is intended as an invitation to understand and integrate the best standards for caring for our collection of works on paper. The more informed the better able you are to preserve and protect your collection.
Deacidification, also called acid neutralization or buffering, is typicalIy the Solution for these types of rapidly deteriorating papers, especialIy for Our libraries and archives. However the deacidification of individual works of art, is entirely different because these processes can alter the colors of paper and pigment or penetrate unevenly thus changing subtle surface textures. Therefore, it is important for collectors to take into account the unique and subjectve qualities of their works on paper, because other less l processes may be preferable for slowing down their deterioration.
Materials and MAS used by artists can also be the unintentional cause of many conservation problems. Paints may be incompatible with one ,mother or with the paper beneath them. This can lead to flaking and staining. Pastels in particular are naturally powdery and certain colors are prone to fading. Proper climate conditions, framing, storage and exhibition can lessen some of the negative effects of the artist's materials on paper.
Additional problems with paper can be caused by external factors, For example, even the best paper will absorb acidity from improper mounting, matting framing, and pollution. Overexposure to light and drastic fluctuations in temperature and humidity can also be damaging Common errors made by enthusiastic colIector, is to place works of art over a working fireplace, bathroom or kitchen, where light exposure and temperature fluctuations are rampant. Clearly, this is not advisable. More obvious external factors include fires, floods, insects, rodents and people, which take a greater toll on prints and drawings than internal generated defects.
MOUNTING & MATTING
Conservators refer to this as acid migraifion. The paper naturally absorbs any gas or liquid that surrounds it. This also includes oils from dirty fingers. Specific to a print or drawing, acidity attacks the chemical bonds of the long flexible cellulose molecules that make Lip the complex structure of paper and breaks them into shorter and shorter segments. (Cellulose, the raw material for making paper, is found in cotton, wood pulp, hemp and other plant fibers.)
The visual symptoms of this process include darkening. yellowing, and embrittlement wherever the paper is in contact with one of the detrimental substances previously cited. Characteristic brown striations caused by corrugated cardboard; shadowy knots of wood transferred onto the paper from a nearby shingle; square patches of discoloration emerging through the design from an identification sticker on the reverse; yellow, even orange, cellophane tape and adhesive stain, are all evidence of contact with common everyday substances that are harmful to paper.
Ironically, these substances are usually hidden from view within deceptively attractive mats and frames so that by the time they make their presence known, the damage has been done. The only way to prevent such damage is for art to be correctly matted before they are framed or put into storage. Therefore, it is important that your framer use archival, museum quality and non acidic tapes, hinges and mats as a means of protecting Your work.
Mats are used to present and protect works of art. I Usually they are made from two sheets of stiff paper board and. joined with cloth or paper tape along their longer edge so that they open and close like a file folder, horizontally or vertically. The bottom sheet of mat board supports the print or drawing while the outer window mat has an opening through which the image is viewed.
It is extremely important to note that paper boards suitable for matting works of art on paper are not automatically used by framers nor are they available at all art supply stores. Therefore, it is essential to specifically request (and be prepared to pay for) conservation-quality mat board. There arc three kinds of mat boa that are suitable for matting works on paper: 1) rag board, 2) buffered rag board and 3) "conservation"board. All of these have a neutral or alkaline pH (a pH of 7 or above) at thetime of their rnanufacture.
As its name implies, rag board is made from cotton rags or liners. Buffered rag board is made alkaline by the addition of a calcium or magnesium carbonate reserve to neutralize acidity. Conservation board, also called museum, archival, or acid-free mat board, is made from wood pulp that has been both chemically purified and buffered. Buffered mat board can significantly retard the degradation of works of art done on acidic, poor quality papers. Conservation-quality boards are now available in a wide range of colors and thicknesses.
The preferred method of securing prints and drawings into mats is with hinges, (small strips of folded, long-fibered Japanese tissue) adhered with purified starch paste. Typically the hinges are applied to the top corners of the back of the artwork. There are many advantages to this type of hinge and placement. Firstly they are strong, flexible and lightweight. They also have an excellent aging characteristic because they allow the work of art to expand and contract freely in response to shifts in temperature and humidity.
Unfortunately, hinges of this sort are not automatically used by commercial framers because of the greater labor and expense involved. In the long run, however, money invested in proper hinging and matting is well spent in comparison with the costs of restoration or loss in value of an artwork damaged by tapes, glues, and cheap mat board.
Many of Lis are familiar with photo corners made of clear polyester film (for example, DuPont Mylar Type D) or acid free paper (not the small black ones found in family photo albums that are especially useful for attaching prints and drawings into mats and often preferable because no adhesives are directly put on the artwork. This eliminates the problem of staining or future hinge removal. These corners can be purchased or home made.
As an informed collector, it is important to be aware that the descriptive phrases "acid-free," "muscum quality," and "archival" are sometimes loosely used and not necessarily a guarantee of quality. Yet, much has changed within the framing industry as they are increasingly responsive to the demand for materials that meet conservation standards. Hence, a new family of pressure-sensitive cloth or paper tapes with a tacky acrylic-based adhesive advertised as "archival" is quickly gaining popularity because of its convenience. However, while the chemical stability of this adhesive is vastly improved, with time these tapes become insoluble in water and require strong solvents for removal. And yet, easy reversibility is normally defined as an archival attribute.
Many collectors find that their passion for work, paper exceeds wall space. Sonic invest in print and others keep their work in large portfolios it they have not framed the work. However, most matted work that is unframed should be protected by a hp sheet of neutral g1assine or acid free tissue between the artwork and the window mat. Clear polyester film can be used except in proximity to flaking paints or powdery charcoal, chalk. or pastel because the film's static charge literally will pull pigment particles from the paper.
If for whatever reason, matting and framing a collection of works of art on paper is not feasible at the very least, they should be stored between neutral glassine and acid-free tissue or slipped into folders made of acid-free folder stock. The next step is for the work to be placed in sturdy Solander boxes oi- boxes constructed, from acid-free cardboard, both specifically manufactured for storing prints and drawings. Under no circumstances should you wrap art works on paper in cellophane, wax paper, brown paper bags, or newsprint-, stored against wood or cardboard, or curled inside cardboard tubes.
After being properly hinged and matted, as previously described, the artwork is fitted into the frame The work of art should not conic in contact with the glass or acrylic, which has been placed into the frame, first. Whenever the two touch, moisture can condense and may result in mold growth.This is one of the most important functions of a mat - to provide a "breathing space" that will accommodate the natural movement of the work of art on paper and dissipate any trapped humidity. Spacers or fillets, (narrow strips of mat board or plastic inserted around the perimeter of the frame and hidden from view) by the rabbet, (the lip of the molding) on which the glass rests, can also provide additional space for unmated or particularly, cockled (warped) papers.
Your choice of glass or clear acrylic for glazing should keep conservation considerations in mind. Glass continues to he the usual choice because of its availability and lower price, Its disadvantages include that it breaks easily, is inflexible and cannot withstand torsional stress, and is heavy, In addition, most glass provides no protection against harmful ultraviolet light emitted by all natural and many artificial light Sources.
For these reasons, many people prefer to use rigid clear acryIic, commonly called Plexi or Plexiglas, a registered trademark of one brand). Some acrylics can lessen although not eliminate, damage that is caused by overexposure to light. Works on paper made with paint that appears to be loosely adhered to the paper or actually flaking, should not be framed behind acrylic sheeting. If you find yourself traveling and you pick up a work of art that you intend to bring home yourself, make sure that all art framed behind glass is taped overall to prevent shattering in case of breakage on the road. Make sure that you do not extend tape onto the molding because it will damage gilt or other finishes. Also, never tape Plexiglas because it scratches easily.
It cannot be emphasized enough how important it is to works on paper for temperature and humidity levels to be as constant as possible. Surely seasonal changes are expected in private homes, and apartments, but effort should be made to allow temperature shifts to be more gradual. Conservators recommend 60-70 degrees Fahrenheit and a relative humidity of 45 to 55 percent, plus or minus 5 points, are more reasonably maintained. When the relative humidity rises above 65 percent you run the risk of mold growth due to the water-soluble gums and glycerin used in paper's manufacture. With high levels of humidity, these substances are reactivated and become sticky. Pastels contain similar gums that provide nutrients for sustaining mold growth. At the least fans and air conditioning can circulate air, thus lowering the relative humidity. SO, if you currently have works on paper hanging in your kitchen, bathroom or over an active fireplace, it's time to move them and check to make sure that extensive damage has not occurred.
When you inspect your work for mold growth you will see a whitish haze, feathery strands or small brown spots called foxing Once you identify mold growth or suspect mold growth, you should unframe the art immediately and air it out. This is usually sufficient to stop or prevent the growth since mold cannot survive in less than 65 percent relative humidity Strips of paper soaked with fungicide such as thymol should never be inserted into framed prints and drawings as a preventative measure against mold because it damages many materials and is toxic.
Another indication of unsafe humidity levels for your art is rusty hanging wire and nails. Flaking paint can also be an indication of frequent changes: As the responsive paper expands and contracts below an inflexible paint layer, the attachment of medium to support becomes much weaker. A conservator should be contacted at the first sign of flaking or weakening adhesion of pigment. Your dealer or art advisor should be able to refer you to a few local professionals.
While many collectors may feel helpless in fighting the pollution produced in urban areas, they should be aware that pollution-(particulate and gaseous)-can be produced in the home. Therefore, proper matting and training is one of the most effective means of combating the dangers that degrade paper and cause color changes in certain pigments.
Halima Taha is an art advisor, appraiser and author of"Collecting African American Art: Works on Paper and Canvas."
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