A process is provided for printing an image on a substrate, the process comprising applying to the substrate an ink composition which comprises a liquid medium and a compound of Formula (1 ); wherein: A and D each independently represent optionally substituted aryl or optionally substituted heteroaryl; E represents optionally substituted pyrazolyl; Z represents H, halogen, nitro, cyano, hydroxy, amino, carboxy, optionally substituted alkyl, optionally substituted alkoxy or optionally substituted aryloxy; and p is an integer from 0 to 5; provided that E does not have an optionally substituted carbonamide group of formula - CONR 1 R 2 directly attached to it, wherein R 1 and R 2 each independently represent H, optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl. The printing is preferably ink jet printing. Also provided are compounds of Formula (1 ) and ink compositions containing the same.