I-potassium ferrocyanide (K₄[Fe(CN)₆]) — usawoti oyi-crystal ophuzi osetshenziswa ekuthwebuleni izithombe nge-cyanotype, njengesihlanzi sewayini nanjenge-reagent yokuthola insimbi kusixazululo (ukuhlolwa kwe-Prussian blue). Nakuba iqukethe amaqembu e-cyanide, inhlanganisela uqobo ayinabo ubuthi ngoba inkimbinkimbi yensimbi ne-cyanide iqine kakhulu.