Editing Paper clip (section)

==Shape and composition==
Paper clips usually have an oblong shape with straight sides, but may also be triangular or circular, or have more elaborate shapes. The most common material is steel or some other [[metal]], but molded [[plastic]] is also used. Some other kinds of paper clips use a two-piece clamping system. Recent innovations include multi-colored plastic-coated paper clips and [[spring (device)|spring]]-fastened [[binder clip]]s.<ref>{{Cite web|url=https://www.scientificamerican.com/article/the-paper-clip/|title=The Paper Clip|last=Brown|first=Peter|date=September 1, 2009|website=Scientific American|access-date=December 12, 2018}}</ref> Regular metal paper clips weigh about a gram.<ref>{{Cite web |title=Metric Mass (Weight) |url=https://www.mathsisfun.com/measure/metric-mass.html |access-date=2024-06-17 |website=www.mathsisfun.com}}</ref>