While trying to improve the adhesive that 3M used for tape, Silver discovered a less sticky glue.
Ordinary adhesives are flat, with a solid contact area for adhesion. It is this unbroken contact that makes glue so sticky. What Silver found was a glue that while quite sticky, could only be formed into individual spheres the thickness of a piece of paper. The spheres would only adhere to things tangentially, thus, the adhesive's total contact area was very small. The result was a tacky, reusable glue that held paper together well.
Silver knew he was on to something, but wasn't sure how to market it.