Conservation Framing Techniques for Works on Paper

Conservation framing is the most commonly agreed-upon term to use when referring to picture framing techniques that protect works on paper. However, many picture framers use the terms conservation framing or museum framing interchangeably with preservation framing. Truthfully, it matters not to your work on paper what you call it. What does matter is that preservation framing is properly done to help preserve and protect artwork in accordance to standards set by The Library of Congress.

Over the years, 15th Street Gallery has taken many workshops on the subject of preservation framing. We even had a Denver conservator who specializes in preservation framing works on paper come to the gallery to offer an in-service class to our staff.

Additionally, we have read numerous articles and books on the subject.

To distill it all we describe conservation picture framing as having 4 broad principles: reversibility, pH neutrality, separating glazing from the art, and ultra-violet protection. The basic goal of all 4 of these principles is to make certain that the integrity of the work, if separated from the framing, is undamaged and in its original state. Simply put, nothing the picture framer does should in any way permanently alter the work. Nothing.

Reversibility

In short, everything the picture framer does in the framing of a work on paper should be easily reversed. This means that no work on paper should be – heaven forbid – taped, glued or somehow permanently mounted to the substrate.

That last point is worthy of a little elaboration. The work on paper should never be mounted permanently by heat, glue, pressure or any other mounting method. These mounting techniques are not easily reversed and put the work on paper at great risk. Taking this a step further, we don’t recommend the use of linen tape or any other pressure-sensitive tape that the picture framing industry is so fond of.

Yes, as many framers will tell you, most of these products are “acid-free”, but a picture framer would be hard-put to find a paper conservator willing to endorse their reversibility. That’s right: these tapes go on easily, but they are very challenging to get off; they are not readily reversible. Linen and pressure sensitive tapes can leave a residue on the paper; they have, in some instances, leached color from the art, and paper fibers can be removed when one attempts to take them off.

These tapes provide an easy solution for picture framers, but they are bad for the artwork. They can devalue or even destroy an artwork on paper. When hinging a work on paper to the pH-neutral substrate, we are very “old-school”. We only use the traditional hand-torn Japanese paper hinges made from the vegetable fibers of the kozogami plant. The long, strong fibers of this plant produce very strong dimensionally stable papers that are perfect for the hinging of works on paper. The only adhesive we use is equally as “old-school”.

Its base is ethyl alcohol which is a completely reversible. It leaves no residue when removed.

These techniques take time and skill to employ, but the fruits of one’s labor are priceless. The artwork is permanently protected.

pH Neutrality

This principle relates directly to matting and substrate, and all other paper that is in direct contact with the artwork. There are many “acid-free” mats used in the picture framing industry. Some good; others not so much. Again, we’re old-school on this one.

For original art, we recommend only cotton rag mats with a pH value of 7 or greater. Mats of lesser quality, including those ghastly ground wood pulp boards that are cheap, can damage a work on paper by slowly (or in the case of cardboard, quickly) destroying the paper fibers, often leaving unsightly acid burns. Ground wood pulp mats contain a high level of acid and can transfer to papers that have come in contact with them.

Even ground wood pulp mats that have been lined with rag matting can leave a “burn line” around the work on paper if the bevel edge of the mat is left exposed. These acids migrate or “leak over”. We don’t ever use ground wood pulp boards.

Separating the Glazing from the Art

This is another vital component of conservation framing. No protective glazing (either acrylic or glass) should ever lie directly on the artwork. Glazing resting directly on the art can, and usually does, cause serious damage; the art work can actually stick to the glazing, making it impossible to remove. Sometimes, owing to direct pressure, the inks, paints, or pastel can actually transfer to the glazing.

If an artwork is framed with an aperture mat, sometimes referred to as window mat, the work on paper is automatically separated from the glazing which sits on the mat not the art.

Now, if a piece is float mounted which simply means the edges of the piece are exposed and the actual mat sits under the art, another conservation measure is needed to separate the glazing. We always sit the glazing on spacers which fit under the lip of the frame lifting it from the floated work on paper. Some picture framers use plastic spacers that come in long strips. Using these is not a violation of conservation framing. They do the artwork no harm. We prefer to cut strips of rag mat because they match the float mat so they’re more aesthetically pleasing.

But either way, spacers are vital.

Ultra-Violet Protection

To be honest, many picture framers don’t include this one, but we do. Paper is very fragile. It is subject to atmospheric pollution, heat, humidity, insets, chemical damage, man’s dirty hands… the list is seemingly endless.

Paper is a web of vegetable fibers, usually linen, cotton, wood and mulberry. Paper is, by nature, fragile; it must have protective glazing when framed. However, even with protective glazing, paper is subject to fading if it is not covered with one of the many ultra-violet protecting glasses or acrylic. All light fades, but direct light dramatically fades a work on paper. The effect of light on art can be very gradual and insidious. It may not be immediately evident, and is often difficult to assess until the damage has been done.

We always go over all the UV protecting choices when designing a picture frame.

So, it matters not what a picture framer calls it: conservation framing, preservation framing or museum mounting. What difference does it make? But what does matter is the proper use of the proper conservation materials.