This Day in History Class is a production of I Heart Radio. Hello and welcome to This Day in History Class, a show for those interested in the big and small moments of history. I'm Gay Bluesier, and today we're talking about post it notes, a humble, plentiful office supply, and the best sticky square since the waffle. So, Michelle, what are you up to? Okay, Um, I invented post it's you're kidding? You must have made a fortune. Well yeah, no offense, Michelle, But how in the world did you think of post it I invented a special kind of glue. Oh really, Well, then, I'm sure you wouldn't mind giving us a detailed account of exactly how you concocted this miracle glue, would you now? Um? The day was April six. Post It notes were sold in US stores for the first time. Also known as sticky notes, the small square pieces of paper each had a strip of readherable glue on the back. This allowed a post it note to be attached to a document or other surface, and then to be removed and reused later, all without leaving behind any sticky residue. Post It notes caught on fast with American office workers and were later adopted internationally as well. Today, the little yellow squares are a fixture of office supply closets around the world, with more than fifty billion of them produced by the three M Company each year. But that office revolution didn't happen overnight. It may not sound like a revolutionary idea, but the special glue that's used in posted notes really was a game changer, although at first no one knew it. The glue was first developed in nineteen sixty eight, a full twelve years before posted notes made it to market. At the time, Spencer Silver was working as a chemist for three M, a multinational conglomerate based in Minnesota. His job was to come up with new and better adhesives for use in various industries, but the results didn't always match up with their intended use. For example, when Silver developed the glue used and posted notes, he was actually trying to create a stronger, more reliable adhesive for the construction of airplanes. Instead, he wound up with a weak adhesive, one that could be removed easily while still remaining sticky enough to be reapplied somewhere else. The secret to that reuse of aility was something Silver referred to as micro capsules or microspheres, little blobs of plastic adhesive that could be spread across the surface and then activated when pressure is applied. When you stick a post it note on an object, some of those microspheres on the back of the paper come in contact with the object surface and hold the note in place. Then, each time you unstick that note and attach it somewhere else, some of the remaining microspheres will take over for the used ones. Eventually, though, all the blobs of glue will either be used up or become so blocked by dirt and dust that the note just won't stick anymore. Luckily, you probably have a pad of a few hundred more to keep you going. Silver knew his glue wouldn't work for building airplanes, but he still thought it had to be useful for something. For the next several years, the chemists sang the praises of microspheres and even gave an entire present take on them at a company seminar, But none of his colleagues at three M saw much merit in the idea, so the micro spheres went on the shelf and Silver moved on to other projects. It wasn't until nineteen seventy four that a practical use for Silver's invention was discovered. It happened by chance when another three M employee named Art Fry was looking for an efficient way to mark pages in his hymn book. Fry went to choir practice at his church every Wednesday evening, and he would bookmark the songs for that week with pieces of paper. However, by Sunday morning, all the slips would have inevitably fallen out. He considered using strips of tape, but removing them would have damaged the pages. Fry recalled that readhering glue was something Silver had talked about years earlier, so he asked if he could have some to use for bookmarks. Silver obliged, and after Fry applied the glue to the edges of some scraps of yellow pap his hymnal troubles were over. Fry was so taken with the glue that he made more bookmarks and began using them to leave notes on files at work. Eventually, his coworkers started asking for bookmarks to use in their own offices. Fry whipped up a batch, and pretty soon the staff was writing messages on the bookmarks and leaving them around the office. It was then that Fry realized they had stumbled on something big. He later recounted the epiphany, saying, quote, I thought, what we have here isn't just a bookmark. It's a whole new way to communicate now. It's worth noting that although Silver and Fry claimed to be the co inventors of the post it note, and three M backs up their claim, another inventor named Alan Amron, says that he actually came up with the idea first. He sued three M, claiming that he had brought his press on sticky notes invention to the company back in seventy four. Three M eventually settled the suit with a cash payment to Amron, but the company has continued to cite Silver and Fry as the true inventors of the product. It's unclear what exactly happened all those years ago, but it's conceivable that Amron brought a similar product to three M the same year that Fry and Silver developed their's. Three M ultimately rejected Amron's idea, just as the company initially did with Fry and Silver's. Eventually, though, three M gave in and moved forward with the version of the product that had been developed in house. Yet, even with a clear practical use in mind, three M wasn't convinced that a sticky stack of paper would actually sell. It took several more years of back and forth, but finally, in nineteen seventy seven, the company agreed to test market Silver and Fry's product in four US cities under the name Pressing Peel Notes. Unfortunately, that campaign fell flat. Hardly anyone bought the product, and three M quietly pulled it from shelves in early The disappointing sales seemed to reinforce management's view that sticky notes were not a winning idea, but by that point much of three m's workforce were firm believers in the product. After all, they'd used it themselves for years. This support was enough to convince the company to give it one last try, so in nine three M rebranded the product as post it notes and launched a plan known internally as the Boise Blitz. They sent large numbers of free samples to offices throughout the metro area of Boise, Idaho, and then waited to see how many companies were willing to pay for additional units. Two three M shock, more than nine cent of the company's given samples reordered the product. The results spoke for themselves. Saw On April six, three M released post it notes nationwide. The following year, distribution was expanded to Canada in Europe, and later to just about everywhere in the world. In an increasingly digital world, post it notes still hold their own on bulletin boards, files, computers, desks, doors, art installations, and probably even some church hymnals talk about staying power. I'm Gabe Lousier and hopefully you now know a little more about history today than you did yesterday. You can learn even more about history by following us on Twitter, Facebook, and Instagram at t d i HC Show, and if you have any comments or suggestions, you can send them my way at this Day at iHeart media dot com. Thanks to Chandler Mays for producing the show, and thank you for listening. I'll see you back here again tomorrow for another Day in History. Class se

This Day in History Class is a production of I Heart Radio. Hello and welcome to This Day in History Class, a show for those interested in the big and small moments of history. I'm Gay Bluesier, and today we're talking about post it notes, a humble, plentiful office supply, and the best sticky square since the waffle. So, Michelle, what are you up to? Okay, Um, I invented post it's you're kidding? You must have made a fortune. Well yeah, no offense, Michelle, But how in the world did you think of post it I invented a special kind of glue. Oh really, Well, then, I'm sure you wouldn't mind giving us a detailed account of exactly how you concocted this miracle glue, would you now? Um? The day was April six. Post It notes were sold in US stores for the first time. Also known as sticky notes, the small square pieces of paper each had a strip of readherable glue on the back. This allowed a post it note to be attached to a document or other surface, and then to be removed and reused later, all without leaving behind any sticky residue. Post It notes caught on fast with American office workers and were later adopted internationally as well. Today, the little yellow squares are a fixture of office supply closets around the world, with more than fifty billion of them produced by the three M Company each year. But that office revolution didn't happen overnight. It may not sound like a revolutionary idea, but the special glue that's used in posted notes really was a game changer, although at first no one knew it. The glue was first developed in nineteen sixty eight, a full twelve years before posted notes made it to market. At the time, Spencer Silver was working as a chemist for three M, a multinational conglomerate based in Minnesota. His job was to come up with new and better adhesives for use in various industries, but the results didn't always match up with their intended use. For example, when Silver developed the glue used and posted notes, he was actually trying to create a stronger, more reliable adhesive for the construction of airplanes. Instead, he wound up with a weak adhesive, one that could be removed easily while still remaining sticky enough to be reapplied somewhere else. The secret to that reuse of aility was something Silver referred to as micro capsules or microspheres, little blobs of plastic adhesive that could be spread across the surface and then activated when pressure is applied. When you stick a post it note on an object, some of those microspheres on the back of the paper come in contact with the object surface and hold the note in place. Then, each time you unstick that note and attach it somewhere else, some of the remaining microspheres will take over for the used ones. Eventually, though, all the blobs of glue will either be used up or become so blocked by dirt and dust that the note just won't stick anymore. Luckily, you probably have a pad of a few hundred more to keep you going. Silver knew his glue wouldn't work for building airplanes, but he still thought it had to be useful for something. For the next several years, the chemists sang the praises of microspheres and even gave an entire present take on them at a company seminar, But none of his colleagues at three M saw much merit in the idea, so the micro spheres went on the shelf and Silver moved on to other projects. It wasn't until nineteen seventy four that a practical use for Silver's invention was discovered. It happened by chance when another three M employee named Art Fry was looking for an efficient way to mark pages in his hymn book. Fry went to choir practice at his church every Wednesday evening, and he would bookmark the songs for that week with pieces of paper. However, by Sunday morning, all the slips would have inevitably fallen out. He considered using strips of tape, but removing them would have damaged the pages. Fry recalled that readhering glue was something Silver had talked about years earlier, so he asked if he could have some to use for bookmarks. Silver obliged, and after Fry applied the glue to the edges of some scraps of yellow pap his hymnal troubles were over. Fry was so taken with the glue that he made more bookmarks and began using them to leave notes on files at work. Eventually, his coworkers started asking for bookmarks to use in their own offices. Fry whipped up a batch, and pretty soon the staff was writing messages on the bookmarks and leaving them around the office. It was then that Fry realized they had stumbled on something big. He later recounted the epiphany, saying, quote, I thought, what we have here isn't just a bookmark. It's a whole new way to communicate now. It's worth noting that although Silver and Fry claimed to be the co inventors of the post it note, and three M backs up their claim, another inventor named Alan Amron, says that he actually came up with the idea first. He sued three M, claiming that he had brought his press on sticky notes invention to the company back in seventy four. Three M eventually settled the suit with a cash payment to Amron, but the company has continued to cite Silver and Fry as the true inventors of the product. It's unclear what exactly happened all those years ago, but it's conceivable that Amron brought a similar product to three M the same year that Fry and Silver developed their's. Three M ultimately rejected Amron's idea, just as the company initially did with Fry and Silver's. Eventually, though, three M gave in and moved forward with the version of the product that had been developed in house. Yet, even with a clear practical use in mind, three M wasn't convinced that a sticky stack of paper would actually sell. It took several more years of back and forth, but finally, in nineteen seventy seven, the company agreed to test market Silver and Fry's product in four US cities under the name Pressing Peel Notes. Unfortunately, that campaign fell flat. Hardly anyone bought the product, and three M quietly pulled it from shelves in early The disappointing sales seemed to reinforce management's view that sticky notes were not a winning idea, but by that point much of three m's workforce were firm believers in the product. After all, they'd used it themselves for years. This support was enough to convince the company to give it one last try, so in nine three M rebranded the product as post it notes and launched a plan known internally as the Boise Blitz. They sent large numbers of free samples to offices throughout the metro area of Boise, Idaho, and then waited to see how many companies were willing to pay for additional units. Two three M shock, more than nine cent of the company's given samples reordered the product. The results spoke for themselves. Saw On April six, three M released post it notes nationwide. The following year, distribution was expanded to Canada in Europe, and later to just about everywhere in the world. In an increasingly digital world, post it notes still hold their own on bulletin boards, files, computers, desks, doors, art installations, and probably even some church hymnals talk about staying power. I'm Gabe Lousier and hopefully you now know a little more about history today than you did yesterday. You can learn even more about history by following us on Twitter, Facebook, and Instagram at t d i HC Show, and if you have any comments or suggestions, you can send them my way at this Day at iHeart media dot com. Thanks to Chandler Mays for producing the show, and thank you for listening. I'll see you back here again tomorrow for another Day in History. Class se