The Arthur Salm Foundation

Report No. 2

Foreign-Produced Paper Products
Used for Philately

This report includes a wide variety of philatelic paper products that are manufactured and marketed in nations other than the United States. These are included as part of the Collectors Club of Chicago (CCC) cooperative program with the Fédération Internationale de Philatélie (FIP), whereby the Salm Foundation will tests materials for worldwide stamp federations at the Foundation's expense. Since this program was first introduced at an international exhibition in November 1991, the CCC’s Salm Foundation expects this aspect of testing procedures to increase in the coming years.

Reports other than those being published by the Salm Foundation have indicated that the paper normally used for the production of postage stamps by the worldwide postal administrations are highly acidic. If an acidic stamp is mounted on an alkaline album page (one that has a pH of 7.0, or greater), the possibility exists that the acidic content in the stamp might migrate onto the page. This transformation is dependent on a number of factors, to include the degree of acidity, the humidity of the storage conditions, type of mount, gum, ink, taggants (a chemical or physical marker added to materials to allow various forms of testing), and other materials introduced into the stamp paper. If the album page is acidic (a pH being below 7.0), then the acid from the page might migrate onto the stamp mounted on the page, although the degree and time span for such a reaction may vary greatly. The stamp dealers trade has reported on numerous occasions the large number of stamps and cover collections ruined by the acidic materials used to mount these items.

Alkaline Reserve is defined as the amount of alkaline buffer present in the paper. This is usually expressed as a percent of calcium carbonate. The material maintains the alkalinity of the paper, since the acidity is prone to cause degradation. Numerous paper mills now are offering alkaline paper since the Arthur Salm Foundation Report No. 1 report was published (March 1991). Also, numerous states have passed legislation requiring that non-acidic paper must be used for all government documents.

Stamp Hinges

Stamp hinges are one of the philatelic products most used by stamp collectors. When the original stamp hinge test results were received, second tests were conducted on the most popular name-brand stamp hinges to confirm the original results; no differences were found. Not one brand of stamp hinge manufactured in the United States was found to be non-acidic.

The Swedish-brand hinge, Novofold, was alkaline. In order to determine how one manufacturer could produce a glassine hinge that was acid-free, the independent laboratory was engaged to conduct further tests on the Swedish hinge, comparing the analytical results to one of America's leading hinge brands, Fold-O-Hinge. Separate tests were requested for the glassine, and for the glassine’s adhesive. The laboratory test procedures were as follows:

  1. Prior to the testing procedures, the samples were conditioned at a standard Technical Association of the Pulp and Paper Industry (TAPPI) temperature of 73ºF and 50% relative humidity; all of the requested qualitative and quantitative test procedures were performed in accordance with standard TAPPI testing methods.
  2. A cold extraction pH test was prepared from the two samples using 1.0 gram sample + 70 ml distilled water. The mixture was covered with a watch glass, and was allowed to stand for one hour at room temperature. The mixture was stirred three times at regular intervals to insure the total wetting of stamp hinges, and the total solution of the mucilage adhesive.
  3. After one hour, the liquid portion was decanted into a second 100 ml beaker, and the liquid samples were saved for their pH determinations.
  4. The remaining stamp hinges were washed three times with 10 ml portions of distilled water; the washings were discarded. 70 ml of distilled water was added to the beakers with the hinges, and the samples were allowed to stand for one hour at room temperature preparing for pH determinations

The pH readings were conducted on the first wash water, and on the water extract of the washed hinges, with the following results:

 

Stamp Hinges pH Readings
Sample Test No. 912-19 912-21
Hinge Brand Fold-O-Hinge Novofold
pH Before Aging 5.8 7.1
pH After Aging 5.4 6.7
pH pH Unaged Reserve 0.0 0.5
pH Aged Reserve 0.0 0.5
pH of Adhesive Solution 5.4 7.2
pH of Washed Paper 6.1 7.1
 

Glassine paper is a smooth, transparent paper manufactured from chemical pulps that have been heavily machined. This type of paper is grease proof, and when waxed, is practically impervious to air and vapors. Sample 912-21 (Novofold) is a transparent glassine type of paper. Under normal manufacturing conditions, the glassine should be slightly acidic, but it appears that some type of unknown alkaline process was employed to manufacture the Swedish hinge.

Conversely, Sample 912-19 (Fold-O-Hinge) is a semi-glassine, parchment-type paper that has not been subjected to as much machining as a true glassine. Parchment-type papers of this type are less transparent than glassine, having a white opaque color. The Novofold and Fold-O-Hinge adhesives were analyzed, and both were starch-based adhesives

The following test procedures were conducted to determine the taste, peelability and adhesion of the stamp hinges. Due to the variability of the adhesives found on postage stamps, the tests were performed on hinges affixed to album pages only, and not to stamps.

Prior to the testing procedures, the samples were conditioned at a standard TAPPI temperature of 73ºF and 50% relative humidity; all of the requested qualitative and quantitative test procedures were performed in accordance with standard TAPPI testing methods.

  1. Thirty hinges were selected at random from each of the name brand sealed packages of hinges. The hinges were manually mounted individually on an alkaline-grade stamp album page, being moistened with saliva.
  2. At the time of moistening the hinge with saliva, the taste of the adhesive was recorded: Pleasant, Satisfactory or Starchy.
  3. After one week of storage at room temperature and humidity, the hinges were manually peeled from the album page, and observed for ease of removal, completeness of removal, and tearing.

On the basis of the observations, the hinges were rated for Peelability (Poor or Good), Hinge Strength, and whether the Hinge Tears, or Does Not Tear. If the result determined "10% tear", this indicates that 10% of the hinges that were affixed to the page tore off without leaving a residue on the album page. Peelable indicates that all the hinges were removed from the album page without a residue.

If the pH value is 7.0 the sample is neutral. pH values lower than 7.0 are acidic, and pH values higher than 7.0 are alkaline. It should be noted that a pH 4.0 is ten times more acidic than a pH 5.0, and one hundred times more acidic than pH 6.0.

This is based on data sourced from the United States National Bureau of Standards, and the widely used permanent paper standard America National Standards Institute (ANSI) No. Z39.48

Stamp Hinges
Hinge Brand Test No. pH pre- Aging Peel and Tear* Taste Adhesion
CMC 918.43 4.8 P Pleasant Good
Dennison No 4 912.16 5.4 50%T Pleasant Good
Dennison No 64 912.17 5.1 50%T Pleasant Good
Dennison No 54002 918.24 5.6 P Pleasant Good
Fold-O-Hinge 912.19 5.8 50%T Pleasant Good
ExactaPhil 918.21 5.0 10%T Pleasant Good
G & K Hobby 912.20 5.6 PT Satisfactory Good
Stanley Gibbons 922.1 5.7 75%T Starchy Good
La Mor 918.22 5.3 100%T Pleasant Good
NovoFoldfactory Good 912.21 7.1 PT Satisfactory Good
Scott 918.23 5.8 50%T Pleasant Good
Western Stamp 912.18 5.12 P Pleasant Good

Details for the qualitative and quantitative analysis performed on the fifty-five philatelic accesory products tested are included in the following table, with the types of items including Album Pages, Album Suppements, Drying Books, Glassines, Mounts, Stock Sheets and Transparent Interleaves

Key to Abbreviations and Notations

AB = Album, Soft or Hard Cover

AC = Album Publ. Co., Germany

AP = Album Pages

ARA = Alkaline Residue Aged: amount of alkaline buffer present in the sample, reported as % Calcium Carbonate

AS = Album Page Supplements

ARU = Alkaline Residue Unaged: amount of alkaline buffer present in the sample, reported as % Calcium Carbonate

BR = Blue Ribbon Co.

Composite = Reports are based on the paper portions only

CS = Canadian Supply Co.

DB = Drying Books

DV = Davo Co.

GD = Grain Direction. As paper is being manufactured, the fibers generally align only in one direction. Paper is produvced in both long and short grain versions

GI = Stanley Gibbons Ltd., London, England

GL = Glassines

GO = Godden Ltd.

HA = Harco Co.

HG = Hagner Co.

KB = Ka-Be GmbH, Hamburg, Germany

LG = Long Grain Direction. Long Grain refers to paper when the fibers run parallel to the long edge of the paper.

LD = Lindner Co.

LI = Lighthouse GmbH, Hamburg, Germany

MA = Marlate Co.

MT = Mounts

pH = (Fr. potentiel Hydrogène = potential Hydrogen). Defined as the negative log of the hydrogen ion activity in an aqueous solution. The pH is a measure determining how acidic or basic a substance is. The pH scale ranges from 0.0 to 14.0. A pH less than 7.0 is acidic, and a pH greater than 7.0 is basic. Pure water had a pH value of 7.0.

pHA = pH After Aging

pHB = pH Before Aging

SB = Stock Book

SC = Scott Publ. Co., Sydney, OH

SG = Short Grain Direction. Short Grain paper refers to paper when the fibers run parallel to the short edge of the paper.

SS = Stock Sheets

TI = Transparent Interleaves

UE = U.S. Envelope Co., Ridgefield, NJ

UP = University Products Co., Holyoke, MA

WR = Worcester Envelope Co., Auburn, MA

--- = Test Not Performed

Philatelic Products
Qualitative and Quantitative Analytical Data
Description Test No. pHB pHA GD ARU ARA
AC - AP 918.3 7.8 8.0 L 6.0 5.9
BR - SB 918.18 7.3 5.8 S 0.0 0.0
CS - AB 918.18 7.0 5.8 L 0.0 0.0
Crown - AB 918.8 7.0 5.4 L 0.0 0.0
DV - 1990 USA AS DV5564H 923.1 7.7 7.2 L 9.2 10.1
DV - 1990 USA AS DV5564H - Composite 923.1A 7.1 5.8 L 7.9 7.2
DV - 1990 USA AS DV5569H 923.2 7.2 7.2 L 9.2 8.6
DV - Black SS DV8429 923.3 6.4 --- S --- ---
DV - White SS DV8419 923.4 6.7 --- S --- ---
DV - USA Blank AP, Border DV5500PO 923.5 5,5 --- L --- ---
DV - Quadrilled AP DV6876 923.6 7.7 7.2 L 9.6 8.2
Disney - AB - World of Stamps 923.24 5.2 --- S --- ---
Fulton - AB - Columbian 923.23 6.0 --- S --- ---
GI - AP - Tower, Leaves 332 923.7 5.4 --- L --- ---
GI - AB -Senator Standard 0387 923.8 5.1 --- S --- ---
GI - AB - Simplex Medium 3811 923.9 5.2 --- L --- ---
GI - AB - Exeter / Plymouth 3833 923.10 5.6 --- L --- ---
GI - AB - Exeter / Plymouth 3833 - Composite 923.10A 5.3 --- L --- ---
GI - AB - Universal 3862 923.11 5.8 --- L --- ---
Disney - AB - World of Stamps 923.24 5.2 --- S --- ---
GI - AB - Universal 3864 923.12 7.2 6.7 L 2.1 2.2
GI - AB - Universal 3864 - Composite 923-12A 6.5 --- L --- ---
GI - Universal Black SS 3866 923.13 4.7 --- S --- ---
GI - Universal Black SS 3866 - Composite 923-13A 4.8 --- S --- ---
GI - AB - One Country 3268 923.14 7.4 7.0 S 12.2 10.6
GI - TI 3311 923.15 5.3 --- S --- ---
GO - AB - Unfaced Warwick 923.17 6.9 6.5 L --- ---
GO - AB - Warwick with TI 933.17A 6.8 6.4 L --- ---
HG - SS - Black 918.45 6.6 6.4 S 0.8 0.8
HG - SS - White 918.45A 6.7 6.5 S 0.6 0.6
HA - AP - Generic for SC Type 918.5 6.8 5.7 L 0.0 0.0
HA - TI - For SC Specialty 918.13 6.85.9 --- --- --- ---
HA - SS - Manila Strips 918.14 8.2 8.2 S 0.2 0.2
HA - Jumbo Art Corners - Composite 918.25 5.3 --- --- --- ---
KB - AB - NR 92 LF 918.9 7.3 5.9 L 0.2 0.0
KB - AP -Blank Quadrilled, Bordered 923.18 5.4 --- L 0.2 0.2
LI - Stockbook 918.16 5.8 --- --- --- ---
LI - Stocbkook Composite 916.16A 5.2 --- L --- ---
LI - AP - Blank 923.16 6.2 --- L --- ---
LN - AS- USA 1988 512 918.7 7.0 6.5 L 0.0 0.0
LN - AS- USA 1988 512 - Composite 918.7A 6.6 5.0 L 0.0 0.0
LN - DB LN845 923.19 6.3 --- S --- ---
LN - AP - Blank Border 802 923.20 7.1 6.8 L 6.6 6.4
LN - AP - Blank Black Border 802D 923.21 5.7 --- L --- ---
LLN - AP - Blank Brown 809 923.22 4.8 --- L --- ---
LN - AP - Blank Brown 809 - Composite 923.22A 5.7 --- L --- ---
MA - Mounts 918.34 5.3 --- --- --- ---
MA - Mounts - Composite 918.34A 5.5 --- --- --- ---
Master - SB - Manila 918.17 7.9 7.1 S 0.2 0.2
Mission Stamp Co. - Supplement 1989 918.12 7.9 8.3 S 8.5 8.6
SC - AP - Quad Border for International Album 918.6 8.1 8.2 L 7.4 7.6
SC - AS - Pony Express 2 918.10 7.9 8.1 S 11.3 11.5
SC - AB - American 48 918.11 7.8 7.7 L 4.0 3.8
UE - Glassines 918.20 5.7 --- --- --- ---
UP - AP - 600-8511 918.3A 8.1 7.6 L 5.7 5.6
WR - Glassines 918.19 6.6 --- --- --- ---

1st Edition, March 1992; 1st Revised Edition, June 2015.