It sure is a great week for nature! This week started with Earth Day on Monday, and the workweek ends with Arbor Day on Friday. Plus, the brilliant spring weather where I live is calling me to go outside and enjoy the flowering trees and green grass. It’s a good time to consider the wonders of our planet!
It’s also a great time to learn about and consider ways to protect and preserve nature. One of the most well known and easily practiced ways to reduce waste and slow the depletion of resources is to recycle. So today I want to write about recycling stamps.
No, not stamps about recycling (like the 2011 Go Green stamp) – about recycling the stamps themselves. I’m going to write about Test Stamps and the Environmentally Benign Pressure Sensitive Adhesive Program of 1994.
Early stamps were affixed to letters by moisture activated gum. In the 1960s and 1970s, governments around the world began experimenting with alternatives to the lick-and-stick method. The first self-adhesive stamp issued by the USPS was issued in 1974, but it was largely unsuccessful due to the new gum making the stamp brittle and discolored as it aged.
But by the mid-1990s, technology had improved, and self-adhesive stamps had become more popular. In addition, address and information labels used by the post office also used self adhesives. The USPS was one of the largest purchasers of PSA (pressure sensitive adhesive) materials, responsible for 12% of the PSA production in the US.
Unfortunately, this advancement in adhesive was a roadblock for recycling. Paper recycling facilities were unhappy with the way that PSAs from stamps and labels on recycled office papers were being processed. The adhesives were difficult to catch and remove during the filtering phase of recycling. PSA material formed globs in the recycling pulp called “stickies” that would pick up dirt and appear as spots and irregularities in the finished recycled paper product.
To help solve the problem, the USPS formed the Environmentally Benign Pressure Sensitive Adhesive Program around 1994. This was a team of researchers from recycling companies, paper manufacturers, stamp printers, adhesive manufacturers, and the Forest Products Laboratory (a division of the US Department of Agriculture). One of the primary goals of the program was to create a new cost effective, easily recyclable adhesive for stamps and labels.
Test stamps were used extensively during this project. Test stamps, also known as “dummy stamps” are an interesting and often overlooked or misunderstood area of philately. These are stamp-like items that were not used to pay for anything – they were used to test machines and processes. It was too expensive to use real valued stamps for experimental purposes, so these dummy stamps were made to the same specifications, but without values. I consider them a lot like stamp essays in that they are trial stamps not issued for use.
And the process for finding a new environmentally friendly adhesive required a lot of trial. Not only did the adhesives need to be tested for their ability to be easily recycled, but they also had to prove they were strong enough to keep stamps affixed through the mailing process. Fourteen different BPSAs were tested during this project. Because the adhesives needed to be able to withstand all types of printing, three designs were used for the tests – each design implemented a different method.
The “Star Spangled Banner” flag design was printed with a five-color gravure process. These were produced in coils and die cut singles, and many were purposely misperforated.
The “Stop Signs” design was printed with a five-color offset and single-color intaglio process. These were printed in several shade variations.
The “George Clinton” design was printed with a single-color intaglio process with overall yellow-green tagging. These stamps were produced in ATM sheetlets of eighteen stamps (two blocks of nine separated by a removable horizontal strip).
In 1998, dummy stamps were affixed to the reverse of 32¢ Liberty Bell envelopes and sent through the mail system. Some of the coil test stamps were applied with affixing machines to test their durability, but most of the test stamps were applied by hand. The Star Spangled Banner stamps were affixed in groups of eight; the George Clinton stamps in groups of eight; and the Stop Signs stamps in groups of five. During the tests, 3.95 million envelopes were mailed. The envelopes sent from different locations across the US to best test their hold during regular use in the mail stream.
Nearly all the test envelopes made it through the mail unscathed, with only 1,000 envelopes damaged. Once delivered, the mail was collected, examined, and sent through the recycling process. Thanks to these tests, a new BPSA was created using a sugar-acrylic polymer that can be easily broken down. In 2000, the USPS revised their specifications for stamp printing to require the use of BPSAs.
And that’s the story of how the USPS helped advance recycling technologies. BPSAs from the program were not only invented for use on stamps but were also used on mailing labels and other office supplies. So if you, like me, opt for recycled or partially recycled papers, you might very well be writing on what was once a postage stamp or someone’s letter!
Although a stamp collector might prefer to give a stamp new life by soaking it off and adding it to an album, if they must be tossed, stamps can also be given new life through recycling!
If you’d like to learn more about test stamps, check out the Dummy Stamps Study Group. Their articles and publications are the best source for US test stamp information.
If you’d like to learn more about adhesives on postage stamps, I recommend watching Exploring Stamps‘s video on the subject.
And if you’d like to help replenish the trees that make the paper for our beautiful stamps, visit the Arbor Day Foundation website to learn about planting trees or donating to fund their programs for a greener world!