Ever wish you could pick the brain of a fine art conservator? Well here’s your chance!

We compiled questions from collectors around the globe about acquiring and preserving works on paper, and posed them to Sarah Melching, Director of Conservation at the Denver Art Museum. 

Learn what materials are more durable than others and which ones will give you headaches and conservation bills for years. Get recommendations for caring for your cherished pieces. Discover what everyday conditions can cause damage to your collection. 

What factors should collectors be aware of when purchasing works on paper?

SM: Here are three important factors:

Exposure to light: Light is the biggest enemy to works on paper. They are very vulnerable to light. Fading of colorants is irreversible whereas if the color of the some papers darkens, it may be possible to improve the appearance with conservation techniques. Pulp containing papers like newsprint will darken and cannot be safely improved with  conservation treatment.

Consider Mark Rothko’s painting that changed in color. He used really thin washes so exposure to light affected the paintings more so than other paintings. Rothko painted a series of murals for Harvard University which eventually faded in the board room. You can learn more about the conservation efforts here.

Quality of the paper: Collectors should also be aware works on poor quality paper. Newspaper and colored paper—such as construction paper—are two examples.

You’ll find artists select poor quality paper as part of their creative process and choice, but it was also the only paper available during war time. It was what artists could get their hands on. Käthe Kollwitz used cheaper papers with wood pulp. Morris Graves would use newspaper. Clyfford Still did a body of drawings on colored construction paper. 

Quality and application of adhesives: When artists work with collage, it’s not only the paper, but the adhesives to consider. And adhesives are important when it comes to the mounting of works. 

The most compatible adhesive for paper would be wheat starch paste, especially for mounting and framing. It can be strong and stable, and it is also reversible. 

Adhesives aren’t really top of mind when buying art. How can collectors learn more and avoid issues down the road?

SM: There is no consistent way. As conservators, we create documentation—written & photographic—around the condition and potential treatment of the piece. We provide recommendations and if treatment is elected, then the process is documented. A collector should ask for documentation when buying from retail galleries, auction houses, estates, etc. Ideally that information is gathered together when selling the piece.  

As an artist, you can track this information and share it with your buyers from your Artwork Archive. And, for those buying the work, you can upload and log the treatments in your Artwork Archive account as well. 

What materials are vulnerable and will need more conservation care?

SM: Watercolor and gouache are vulnerable to fading due to exposure to light. Acrylic and oil can both change in color from light exposure. Oil based-media can also stain paper. 

In general historic processes can be very vulnerable to light exposure, temperature and humidity changes. Art produced during the 19th and 20th centuries are susceptible to degradation if they are made of papers containing wood pulp. In 1839 we shifted from making paper out of cotton to wood pulp in North America because it was cheaper and trees were in abundance. 

Additionally, some prints are challenging. Japanese woodcuts or woodblock prints are highly susceptible to light. Black ink is stable, but if the printmaker added color by hand, that added color can fade.

Fluorescent and commercial printing inks are also vulnerable because posters are intended to be ephemeral, and not created for posterity. 

What new materials should collectors be wary of?

SM: There are so many different media being used in contemporary processes. One thing that has been important in the conservation process is conducting artist interviews. It’s been critical to be able to collect the information from the artist, the studio, or estate. And through your relationship with your conservator, you can work on the best ways to preserve the pieces.

Ballpoint pens, markers, felt tips (sharpies) are also susceptible. They contain a dye. And the dye consists of small particles that breakdown more readily when exposed to light. Sure, a permanent marker does not move with water, but it will fade. Pigment pens are more “permanent” as opposed to a felt tip.

What works on paper media are durable?

SM: Linen and cotton have withstood the test of time. There is a reason why artists make page proofs on those materials. 

Arches paper has been around for centuries and has proven to be quality paper. Rives BFK is a French paper that is durable. Then there is Strathmore paper; Clyfford Still used a lot of Strathmore paper for his oil paint on paper works. 

What is something a collector of works on paper may be surprised to know?

SM: In the later half of the 20th century a lot of commercial manufacturers added optical brighteners. Warhol liked Arches with an optical brightener. Those brighteners can expire due to exposure to light. The background can and will change. Mick Jagger had a bright, luminescent background initially but now it is somewhat darker. 

How can collectors find this information? Gallery assistant notes are a great place to find more information about the materials used. Note to artists reading this article: it’s paramount to document the materials and treatments used in your works. It will ensure the lifetime, longevity and legacy of your works. You can store all of this information in your Artwork Archive account and easily share it in a Portfolio Page report to go along with your sale. 

What is one of the most popular types of work on paper to be collected?

SM: Some collectors like drawings because they are unique and one of a kind. Some like prints because of the processes that have developed throughout the history of printmaking. Artists who worked in the etching medium for instance like that you can rework the plate, creating a different “state.” For instance, Rembrandt re-worked his plates and created different outcomes with each state. Since the late 19th century, many prints were numbered in editions indicating how many are in the series. The size of an edition reflects the exclusivity of the work.

What do collectors usually not think about when it comes to acquiring works on paper?

SM: After their purchase, collectors are excited to be able to frame the piece and put it up on display. They often do not think much about the way the work is framed.

I am often asked what is the best way to frame and preserve a piece. There are materials for conservation framing. I’d recommend contacting a conservator about your particular piece. You can learn more about conservators in this Artwork Archive article.

Ultimately, if you want to preserve a piece, put a drape over it or don’t keep it out all of the time. 

About Sarah:

Sarah Melching received her M.A.C. in paper conservation from Queen’s University in Kingston, Ontario.  She had additional training at the Library of Congress, National Gallery of Canada, and the Fine Arts Museums of San Francisco.  From 1992-2007, Sarah was in private practice in the Pacific Northwest. Sunshine beckoned in 2008 at which time she began working as the paper conservator at the Denver Art Museum.  In 2009, she became the Director of Conservation. Sarah oversees all administrative aspects of the department and continues to conserve works of art on paper and photographic materials. 

Among professional organizations, Sarah is a member of the International Institute for Conservation, the Western Association for Art Conservation, and is a currently board member of the American Institute for Conservation.

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