Printers that have installed centrifuges have found that laundry services will sometimes reduce prices for rag cleaning. When used solvent becomes too dirty to use for any type of cleaning, distillation or filtration can be used to recover clean solvent from the dirty solvent. Small solvent stills to handle as little as one gallon can be purchased to recover solvent. Filter-type solvent sinks are also very good at extending the useful life of solvents. Printing Printing inks can also be a source of air pollution.
Inks are now available that contain no solvent or reduced amounts of solvent.
Water-based inks are available for screen printing, flexographic, gravure, and lithographic printing. Low solvent inks such as soy-based are commonly used to print business forms and newsprint. Besides solvents, inks can also contain toxic metals. Printers should contact ink vendors for blends with reduced metals and solvents. Image or Plate Preparation Image and plate preparation can generate significant amounts of waste.