What is vegetable ink ? Can it be used in web printing ?

The inks used in web printing are dried in an oven (hence its’s also called heat set printing) and contain about 35% of mineral oils. It is technically impossible to replace these with vegetable oils. The oils of the inks are evapored and sucked up to be processed in an afterburning installation. No residu goed in to the open air.
It is possible to print with vegetable ink on a sheet fed press but the ink attaches more firmly on the fibres of the paper and this may impede the recycling of the paper.