Pin fastener is the most common fastener and spans the eras, from edwardian onward, though the very early fasteners closed with a c shapedend instead of a rotating one. Fur clip was designed to be worn on the thick lapels of fur coats, or other heavy materials such as tweed. Not suitable for lighter materials such as wool or silk as the prongs can leave marks, mainly used from 1940s to 1950s, Dress clip is a flattened hinged fastener and was used in the 1940s mainly Duette clip,made by many companies,most famously Coro. Comprises of a frame which allows two brooches to be worn together, the whole mechanism comes apart if you wish to wear the brooches seperately