Post-it^® notes

Date of invention: 1974
Inventors: Art Fry and Spencer Silver, 3M
Country: USA

As with most inventions, a simple need gave creativity a push. In the case of the now-famous Post-it^® note, that need was felt in the early 70's by Art Fry. A worker at 3M, Frey also belonged to the local church choir and was frustrated as his bookmarks kept falling out of his hymnbook.

He knew of an adhesive developed in 1968 by Spencer Silver, a fellow colleague at 3M, who, while attempting to design a strong adhesive, had in its place developed a weak one that was strong enough to stick to surfaces, left no residue after removal and could be easily repositioned. As no immediate application was obvious, the adhesive remained unused until 1974 when Fry had his brilliant idea.

Fry applied some of Spencer Silver's adhesive to part of a piece of paper and solved his falling bookmark problem. He soon realised that his invention had real potential when after using it to leave a note on a work file, co-workers kept dropping by his office, looking for his "bookmarks".

The Post-it^® was born. Today they come in all shapes and sizes, in over 30 different colours and are to be found everywhere: in offices and homes, on files, computers, desks and fridges throughout the world. This invention could almost be called a Godsend, given its original design for use in a hymnbook!

The silicone factor

The adhesive used in Post-it^® notes is silicone-based. It is composed of very long chain linear silicone polymer and a resinous material. It is especially designed to allow the note to stick when a little pressure is applied and to peel away cleanly without tearing or leaving marks on the surface.

» Downloads:
Sealants and Adhesives fact sheet [4Mb]