The structures of four industrially valuable vat dyes are solved for the first time: 1,1′-diethyl-[3,3′-bidibenzo[cd,g]indazole]-6,6′(1H,1′H)-dione (Vat Red 13, Cibanone Red 6B, Carbanthrene Red G 2B, Ahcovat Rubine R), 16,17-dimethoxyviolanthrone (Vat Green 1, Caledon Jade Green, Jade Green Base, Indanthren Brilliant Green B), pyranthrone (Vat Orange 9, Ahcovat Golden Orange G, Benzadone Gold Orange G, Pigment Orange 40), 2,8-diphenylanthra(2,1-d:6,5-d')bisthiazole-6,12-dione (Vat Yellow 2, Anthra Yellow, Tyrian Yellow A-GC) and violanthrene. Violanthrene was obtained by reduction of 16,17-dimethoxyviolanthrone with sodium metal in ethanol. The single crystals were grown by vacuum sublimation and examined with a synchrotron radiation source. The structures of all the four vat dyes represent a stacking motif, whereas violanthrene molecules form sandwiches of two molecules. The interplanar distance between the molecules in the stacks (sandwiches) is 3.35–3.48 Å which is typical of polycyclic aromatic compounds.