What Is an Ink Production Reactor: Varnish Cooking, Dispersion and Letdown Answering the core question: What is an ink production reactor? An ink production reactor is the vessel in which printing ink is manufactured, and it performs three distinct duties. Varnish cooking dissolves or reacts a resin into a solvent or oil at 120-200°C for 2-8 hours to make the vehicle that carries the pigment and binds it to the substrate. Dispersion breaks pigment agglomerates down in a