>The substance on the side of a matchbox is commonly known as the striking surface or the matchbox striker. It is a specially treated surface that facilitates the ignition of matches when they are struck against it. The striker typically contains a combination of phosphorus and other chemical compounds.
the more you know! it's impossible to know what extremely specific things like this are called in a foreign language without googling it. well sometimes I have to google much more common stuff too. if it was a face to face conversation I'd be stuck trying to describe the object and embarrassing myself