Spencer Silver, a research chemist at 3M who inadvertently created the not-too-sticky adhesive that allows Post-it Notes to be removed from surfaces as easily as they adhere to them, died Saturday at his home in St. Paul, Minnesota. He was 80.
His wife, Linda, said that he died after an episode of ventricular tachycardia, in which the heart beats faster than normal. Silver had a heart transplant 27 years ago.
Since their introduction in 1980, Post-it Notes have become a ubiquitous office product, first in the form of little canary-yellow pads — billions of which are sold annually — and later also in different hues and sizes, some with much stickier adhesives. There are currently more than 3,000 Post-it Brand products globally.
Silver worked in 3M’s central research laboratory developing adhesives. In 1968, he was trying to create one that was so strong it could be used in aircraft construction.
He failed in that goal. But during his experimentation, he invented something entirely different: an adhesive that stuck to surfaces but that could be easily peeled off and was reusable.
It was a solution to a problem that did not appear to exist, but Silver was certain it was a breakthrough.
“I felt my adhesive was so obviously unique that I began to give seminars throughout 3M in the hope I would spark an idea among its product developers,” he told Financial Times in 2010.
Silver promoted his adhesive for several years within 3M, a company known for its innovative workplace, so assiduously that he became known as “Mr. Persistent.”
He patented the adhesive (technically called acrylate copolymer microspheres) in 1972. But two more years passed before someone at 3M paid serious attention to it: Art Fry, a chemical engineer in the tape division lab, who was looking to develop new products.
Fry had heard about Silver’s adhesive from a colleague while on the second hole of 3M’s corporate golf course in Lake Elmo, Minnesota, and decided to attend one of Silver’s seminars.
“We didn’t know each other well,” Fry said by phone. “We had crossed paths in things like the bicycle club. 3M always devised ways to mix people from different divisions.”
He did not think of an immediate application for the adhesive until one day, while at church choir practice, he realized that he had a problem that Silver’s invention might solve: The slips of paper that Fry had been using to bookmark songs in his hymnal kept falling out. So he used a sample of Silver’s adhesive to create a bookmark that stayed put but did not tear the pages when removed.
Fry tested a similar bookmark on some co-workers, with positive results. But he needed more proof that there was a product 3M might want to pursue. So he sent a report to his supervisor with a note on the front written on a piece of the bookmark; the supervisor responded on the same piece of paper, with the adhesive on part of the other side, and returned it.
“It was a eureka, head-flapping moment,” Fry told Financial Times. “I can still feel the excitement.”
In 1993, Fry received a patent for the Post-it, or technically a “repositionable pressure-sensitive adhesive sheet material.”
Spencer Ferguson Silver III was born Feb. 6, 1941, in San Antonio. His father, Spencer Jr., was an accountant. His mother, Bernice (Wendt) Silver, was a secretary.
Silver was a teenager in 1957 when the Soviet Union sent the first artificial satellite, Sputnik, into Earth’s orbit.
“His science teacher told the class, ‘All you guys are going to be engineers,’” his wife said in a phone interview.
Silver did not choose engineering or astrophysics. Instead, he graduated from Arizona State University with a bachelor’s degree in chemistry in 1962. He earned a doctorate in organic chemistry from the University of Colorado, Boulder, four years later. While there, he met Linda Martin, an undergraduate who was working part time in the chemistry department. They married in 1965.
He soon joined 3M as a senior chemist working on pressure-sensitive adhesives. During his 30 years at the company, he rose to the rank of corporate scientist. And while he worked on other projects involving branch block copolymers and immuno-diagnostics, none were part of popular successes like Post-it Notes.
The mating of Silver’s adhesive and Fry’s handmade adhesive notes was a hit with 3M secretaries. But 3M executives were not so sure.
A test release in 1977 of Press ‘n Peel, as the product was called, in four cities — Denver; Tulsa, Oklahoma; Tampa, Florida; and Richmond, Virginia — flopped with consumers, who were uncertain about the idea of repositionable paper squares. But the next year, 3M had greater success when it flooded offices in Boise, Idaho, with free samples; 90% of the recipients said they would buy them.
Two years later, 3M introduced Post-it Notes nationally. They have never stopped selling.
“The Post-it Notes took off so rapidly,” Silver told CNN in 2013, “that I think it left a lot of people in marketing and sales gasping a little bit.”
“It was always a self-advertising product,” he added, because customers would put the notes on documents they sent to others, arousing the recipient’s curiosity. “They would look at it, peel it off and play with it, and then go out and buy a pad for themselves.”
Silver and Fry were inducted into the National Inventors Hall of Fame in 2010. Silver received the American Chemical Society’s Award for Creative Invention in 1998.
Silver painted part time during his years at 3M. He pursued art more seriously in retirement, using acrylics, oils and pastels on canvas to create abstract works.
In addition to his wife, a computer programmer who used Post-it Notes to mark and annotate bugs in printouts of programs, Silver is survived by a daughter, Jennifer Silver, and two grandchildren. Another daughter, Allison Anderson, died in 2017.
Post-it Notes played an unlikely role in the 1997 film “Romy and Michele’s High School Reunion.” When asked by her former classmates what she had been doing, Michele (played by Lisa Kudrow) pretends to be the success she is not, 10 years after high school, and says, “OK, um, I invented Post-its,” and then takes on the role of Silver.
“I invented a special kind of glue,” she says, and proceeds to give a gobbledygook explanation of the chemical process involving the need to “thermoset your resin,” mix in “an epoxide” and add “a complex glucose derivative during the emulsification process.”
It was all nonsense provided by Fry when the filmmakers asked 3M for technical help.
“I wrote out a bunch of stuff that had nothing to do with Post-it Notes, and they used it,” Fry told Vice in 2017. “It sounds more like something you would use to repair your broken dining room chair than the adhesive required for Post-it Notes.”