Do you remember the harmless Pon Push Pin? The same folks have a new version (aptly named Pon+) that’s a bit bigger and has a smart pull tab. Pull the tab and slide your pictures/artwork underneath for easy display and no puncture wounds. The bigger size means it can hold larger loads as well.
Each Pon+ 18mm in diameter / 56mm circumference.
Available from Kickstarter, $13.00.