Iron powder grain size 0-63 micron can be mixed into, among other things, Plasikret or acrylic lacquer. It can later be patinated like iron. After treatment with, for example, hydrochloric acid or iron nitrate, a beautiful rusty brown / orange colour develops. Can also be used to make magnetic fields visible. Keep the magnet under a glass plate or paper, otherwise you will not be able to clean the magnet.