|I wanted to keep my latest button acquisitions from the thrift store $1 clothing rack together instead of loose in my button containers. Usually I will thread them together, but the threads would get twisted onto other button loops. Then I spied one of my larger safety pins - they fit on there! Depending upon the button width and size of the safety pin, you can use this with hole and shank buttons.
A lot quicker than "sewing together" with thread and easy to remove as they are needed.