Antique Maps and evaluating condition

Antique maps may sustain many forms of damage over the years, some of which can be easily overlooked in the excitement surrounding a purchase. So it is important for collectors to understand issues related to map condition and exercise care with each acquisition. 

Types of condition problem

Condition flaws may be categorized somewhat arbitrarily as either aesthetic or structural. 

Most aesthetic flaws are static, in that they will not develop further if left alone. These include paper toning, soiling, water staining, manuscript notations, or library ownership stamps. Of greater concern are problems such as foxing, a brownish yellow, patchy discoloration caused by the action of mold on iron salts (see this example) and mildew, usually appearing as blackish, grayish, or purplish splotches. Left untreated, these can progress and even damage a map irretrievably.

The most common structural flaws are creases, tears, puncture holes or wormholes. Less obvious but potentially more serious is deterioration of the paper overall. “Healthy”paper is both supple and crisp at the same time; it should produce a distinctive crackling sound when held at the edges and waved gently up and down. When the fibers in a sheet of paper deteriorate, they can become either brittle and crumbly or limp and spongy. 

Other structural flaws are byproducts of the binding process. Most common are center- or other folds and trimmed margins, both of which reflect the binder’s effort to fit the map within the confines of a book. 

The impact of condition flaws is a function of degree, perception and rarity. The most common problems (e.g., small tears, folds, or a small spot or two of foxing) are acceptable and do not seriously detract from the value of a map. The threshold will vary from person to person and map to map, however: Flaws in a sought-after rarity are more acceptable than similar flaws in a common piece. And one person’s “throwaway” may be perfectly acceptable to another prospective buyer. 

Map conservation

If well executed, conservation improves the aesthetic value of a map, extends its lifetime, and enhances its market value. And skilled conservators are able to work wonders: I have seen maps that appeared all-but unretrievable rendered bright, attractive and durable. 

That said, a well-conserved map is still less valuable than the same map in excellent original condition. Generally speaking, the decrement in value will be directly related to the extent of conservation and inversely related to the intrinsic desirability of the map. 

It is thus important to inspect a prospective purchase for signs of conservation, some of which may be easily overlooked. Some of the most common are closed tears, trimmed margins extended with thin strips of paper, and whole maps stabilized by backing with thin tissue. On maps that have been more seriously damaged, one should also look out for areas of lost image that have been replaced with manuscript facsimile. Here, for example, is a map of Fort Scott, Kansas where part of the title and several inches of the map at upper right have been replaced with facsimile.

Unfortunately, maps can also be damaged by misguided efforts at conservation. Most common are tears closed with cellophane tape, which contains chemicals that will discolor the map and damage the paper. It is also common to find a map glued to a cardboard, foam core or other backing, usually in an effort to stabilize it for framing. Though removal is often possible, chemicals in the glue and/or backing often do substantial damage. Somewhat more subtle is excessive bleaching, which can leave the paper unnaturally bright and seriously weaken its fibers. 

Buyer and bidder beware

The most obvious tool available to the purchaser is the condition assessment provided by the seller. 

At a minimum, most map dealers and specialty auction houses will rate map condition on a scale such as excellent,” “very good,” “good,” “fair,” or “poor.” Such information should be used with care, as there is no standardized condition rating scale: One dealer’s “excellent” may be the equivalent of a more exacting dealer’s “very good.” A related concern is “condition inflation,” a classic form of which is the “otherwise” clause. Here is an exaggerated example: “Paper toned, large tear at lower left with slight loss of image, and a large grease stain (pizza?) at right center, otherwise excellent.”

Many sellers augment their ratings with a description of specific condition problems. However don’t expect these to be comprehensive, as typically only the most important issues are highlighted. This is entirely appropriate: an exhaustive description of flaws can make a perfectly appealing map sound like a throwaway.

Finally, auctions and dealers can and do make honest mistakes; it is all too easy to miss a problem when cataloging under time pressure. 

Thus, while auction and dealer descriptions are a starting point, and catalog images can be helpful, there really is no substitute, there really is no substitute for direct, personal inspection.

Assessing condition

Use the following steps when examining a map in person: 

  1. Visually examine the map front and back, looking for signs of aesthetic or structural flaws as well as repairs. 
  2. Place the map between yourself and a strong light source, and look again for flaws or repairs. Repeat for the other side of the sheet. Strong backlighting will often reveal issues that are otherwise all-but invisible to the naked eye.
  3. Feel the paper (in the margin only, without touching the printed image!) to assess its quality and condition. 
  4. Smell–yes, smell–the paper to detect residual signs of bleaching. 
  5. After you have used your own senses, review the catalogue description and ask the seller what he or she considers to be the significant condition issues. 
  6. Framed maps present special challenges: of particular concern are the condition of the matted-over areas and the possibility that the map has been “laid down” (i.e., glued to a backing). In such cases, always inquire as to whether the map has been inspected out of its frame; if not, we strongly recommend making the purchase contingent on just such an examination. 
  7. When considering a purchase by phone or internet, always contact the seller for more detail about condition. It is also helpful to request a high-resolution jpeg or other image, enabling you to inspect the map more minutely than allowed by the low-resolution web-mounted images or thumbnail illustrations in catalogues. 
  8. Finally, inquire as to the seller’s policy on returns and refunds. Most will allow you to return a map for a full refund within a certain period of time, no questions asked, though you may be expected to cover the cost of return shipping. So long as such a policy is in place, your risk is reduced to essentially zero. Purchasing at auction is a different matter; it is almost impossible to obtain a refund unless the house has grossly misrepresented the item. 


To conserve or not to conserve?

Given the cost of conservation and the ever-present risk that something may go wrong, it is best to leave alone maps already in very good condition. For maps with more serious problems, however, there is no standard answer as to when conservation is merited. All that can be said is that restoration is in order if either

  • It will continue to deteriorate if conservation steps are not taken, and/or
  • The current condition will interfere with your enjoyment of the map 

A very small number of conservation steps can be accomplished by the layperson. Most commonly one may close small tears with acid-free tape or tissue and remove surface soiling with a special document cleaning pad. Appropriate supplies are available from conservation- supply firms such as Talas in New York City ( 

For more involved work, find a professional! Most conservation requires specialized equipment and supplies, a knowledge of materials and chemistry, and lots of practical experience. The website of the American Institute for Conservation of Historic and Artistic Works ( offers a searchable directory and other resources. 

A word for the wise

The intent of this article is not to create panic about condition issues, but to help others become more informed buyers of antique maps. Essentially all antique maps will have some imperfections, however slight, and these should be acceptable… they are, after all, old. Those who pursue only “perfect” copies may miss out on good buying opportunities and prevent themselves from the proper enjoyment of many quite wonderful pieces.

Further reading

Manasek, Griggs & Griggs, Collecting Old Maps. Old Maps, LLC, 2015 (2ndedition). See in particular Chapter 6: “Condition and conservation.”, the website of the Northeast Document Conservation Center, offers extensive information about caring for and conserving works on paper.