This is a low profile bed clip that I use to hold my 3mm polycarbonate build surface to my 3mm aluminum bed. (total thickness ~ 6mm) Use with the "TOP" side up for lowest height above the bed. I made it because the part cooling duct I designed rides too close to the bed for typical bulldog clips. Make from abs for best results. They will gradually loosen up the more they are exposed to high bed temperatures, but can usually be renewed by warming with a heat gun and flexing back.

• Update: 1/21/2018 I still use regular binder clips ~ 90% of the time because any printed clip has a limited lifetime especially if used with high bed temperatures. Eventually they will loose their spring or crack so keep extras on hand. I just use these anywhere my cooling duct or nozzle would be at risk of hitting a binder clip.

Ordinary polycarbonate works really well as a build surface by the way. Works the same as glass except you may need a few more clips to hold it flat. You can flex the poly to pop off stubbornly stuck parts. Just don't use abs juice as that bonds way to well to polycarbonate!