The Arthur Salm Foundation

The Salm Foundation was formed by the Collectors Club of Chicago in March 1991 to conduct research on philatelic products. Funding was donated by the Salm family with the CCC providing a matching grant. Officers, who served without compensation, are Lester Winick, president; Bernard Hennig, Vice President; Jacob Bard, Secretary; and Raymond Vogel, Treasurer.

The Foundation purchased commercial philatelic products manufactured around the world that are sold in the United States. These materials were submitted to a professional commercial laboratory for testing. One problem has been that stamp collectors have found that their album pages show serious deterioration due to acidic conditions present in the paper. This acidic codnition has been found to “migrate” to the postage stamp or cover attached to the page. Paper with low acidity or manufactured under neutral or alkaline conditions, can be expected to contribute signifcantly to the life of the pages and mounted philatelic material.

The CCC published a series of six pamphlets on a variety of philatelic products using an independent laboratory to do the testing. Results included the name and publisher of each item as well as a description. Testing was quite extensive and included album pages, stamp hinges, stock books, corners, glassine envelopes, stamped envelopes, computer paper for printing pages, false stamps, pressure sensitive self-adhesive U.S. stamps, and more. 146 commercial products were tested, not including the various fakes stamps specified in the reports.

More than 4,000 of these reports were distributed throughout the world, and the CCC is proud to state that not a single product was challenged. We did have one challenge from a distributor who threatened to sue the CCC. We asked for a copy of his lab test but he had none. We sent him a copy of our lab test to show to his manufacturer. Very sheepishly, he called to apologize and said that the CCC report was correct.

The six reports are available for a legal or large size self-addressed envelope with $1.06 postage affixed. Send your requests to: Collectors Club of Chicago, 1029 N. Dearborn St., Chicago, IL 60610-2803. Please allow 3-4 weeks for delivery.

Report Number 3

Plastics, Paper Permanence, and Hinges


The Arthur Salm Foundation has spent 2 1/2 years in preliminary study on plastics used in philately in which we have not reached a definitive conclusion because of the many variables involved in the manufacture of plastics for philatelic purposes. The task of defining more precisely which materials are better suited for philatelic archival purposes at this time appears to be beyond the relatively limited resources of the Foundation.

"Archival" is an imprecise non-technical term that has no exact definition. It implies some form of preservation, an extension of an object's life beyond its usual environment; the materials and techniques used in addition to environmental conditions. Such materials are expected to be durable and chemically stable under the anticipated conditions. There are no universal standards as to how long an archival material should last and under what conditions or how it will help preserve materials that were not originally intended to last.

To the philatelist archival implies an environment that will permit most stamps and covers to last from several generations to several hundred years or more in essentially their original condition. Stamps printed on highly acidic paper or those with self-sticking adhesives will most likely decay in the finest archival mounting and atmosphere unless they are professionally treated. Even then, they will still probably not last as long as similar material made from acid-free components. What is reasonable for one is not reasonable for someone else. For example, most stamps would survive better without gum but few collectors want to remove the gum.

Long term preservation of papers involves contact with neutral materials that are free of acid and alkaline salts and do not change when exposed to environmental conditions such as storage temperature, relative humidity and air quality as well as with time. Light, especially sun light is particularly detrimental, as it can be a catalyst to further promote chemical reactions. Finally, of course, handling should be kept at a minimum since simply flexing can weaken fibers and, in the extreme, cause ink to fleck off.

Philatelic protective materials many times are constructed using plastic films, particularly where transparency is of value. The molecular structure of these polymers (plastics) can be tailored to give a wide variety of properties in the end product. Additives are also added to produce a final commercial composition with desired specific properties. There is a very long list of plasticizers, slip agents, stabilizers and inhibitors that are added to most plastics before they are added into films to be used as hobby materials. Beyond that, there are wide variations in stamp inks, paper gum, taggants, overprints, etc. each of which can affect a stamp's interaction with the plastic.

The Foundation has studied several publications issued throughout the world in several languages during the past fifty years evaluating "protective films" as they are used in philately. We have translated, examined and discussed each one very carefully. Further, a rather extensive laboratory evaluation of various plastic materials was made and a 30-page report was submitted to the Board of Directors of the Salm Foundation. After careful and sincere study by the Foundation's board of polymer experts, it was found lacking in several important areas and unscientific in its experimental conclusions. This study will not be released.

At this time, the only specification by a recognized scientific body that can be suggested to the hobby is that of The United States Library of Congress Preservation Office which has very stringent requirements for the "protective films" used for their archival storage: "Composition must be clear, colorless, (biaxially oriented/stressed/drawn) polyethylene-terephthalate film such as DuPont Mylar© D, ICIMelinex© 516 or equivalent. The clear and colorless polyester film must not contain any plasticizer, surface coatings, UV inhibitors, or adsorbents and be guaranteed to be non-yellowing with natural aging. As received, the film must not contain any coloring agents. A certification of compliance with the above requirements must accompany the shipment." (The Library of Congress, Specification Number 400-005-1/93, etc.)

Looking at all of our data, it is apparent that there may be no single class of plastic films, with the possible exception of that noted above, which behaves well in all situations. Unfortunately, we must leave it to the collector to select their materials accordingly.

View results in table format

Testing for Paper Permanence

Prior to testing, the samples were conditioned at standard TAPPI (Technical Association of Pulp and Paper Industry) temperature of 73F and 50% relative humidity and the requested tests were performed in accordance with standard TAPPI methods. The test results applicable to the submitted samples are given in the following data tables.

Permanence of paper refers to the chemical stability of paper and its ability to maintain the initial properties over a long period of time.

Permanence can be measured by an accelerated aging test in the laboratory. In a typical test, the paper is heated in a circulating air oven at 105 degrees C. Seventy-two hours under these storage conditions is equivalent to 25 years of normal paper aging. In this project, the material was aged18 days, equivalent to 150 years of normal aging. It has been observed that alkaline grade papers have better permanence / longevity / shelf life than ordinary acid papers.

There are two manufacturing methods of producing alkaline grade paper: 1. Alkaline filled paper contains calcium carbonate. This paper has a pH value in the range 7.5 to 9.5 and contains a reserve amount of buffering capacity which acts to neutralize acidic chemicals which come in contact with or are produced in the paper during aging. 2. Alkaline sized paper has been sized (chemically treated) in an alkaline paper machine system. This paper has a pH of 7.0 or higher. This type of paper can be sold as is or further coated with calcium carbonate to impart an alkaline reserve.

In the laboratory, a paper sample is tested for pH (acidity-alkalinity) by a cold extraction method. If the pH is found to be in excess of 7.0, the paper sample is considered to be an alkaline grade paper. This type of paper is subjected to an additional test called "alkaline reserve" in which the amount of calcium carbonate present in the sample is determined.

Alkaline grade papers are of interest to a philatelist because they should be used to mount expensive and sometime rare philatelic material. If these items are mounted on an acid paper, the acidity will carry over to the mounted items over a prolonged time of storage and cause physical degradation.

Hinge Testing Procedures

The stamp hinges are affixed manually to an alkaline grade paper. After six days of aging at room temperature conditions, the hinges were removed and evaluated for peelability and tear tendency. The samples were rated for taste during mounting.

100% peelable means that the stamp hinge was readily and entirely removed from the stamp page.

100% tear means that the stamp hinge tore leaving the small "tab" of the hinge on the stamp page (in whole or part). This tear pattern occurred and was observed on all the stamp hinges tested form this particular sample.

100% peelable and 100% tear represent the extremes in which the stamp hinge is completely removed in one case and remains adhered in the second case.