While a good deal of the focus on environmentally sustainable production processes for direct mail and other marketing materials has centered on paper, marketers also can make more eco-oriented choices when specifying inks.
According to The Massachusetts Toxics Reduction Institute (MTRI), vegetable inks replace all or some of the petroleum oil commonly found in lithographic inks with, you guessed it, vegetable oil. Some of the vegetable-based oils used include soy, linseed, tung, cottonseed and china wood oil, notes Barefoot Press, and all are biodegradable. This green-minded printing company explains, on its website, that the big concern with petroleum-based inks is that they contain "ozone-damaging distillates and volatile organic compounds (VOCs)."
But just because an ink contains vegetable oil doesn't mean it's as green as green can be. When assessing the value of "veggie ink," it helps to know a few facts about what they might be and how they perform:
- Soy ink can contain as much as 60 percent petroleum, reports Guy Dresser, in a seminar presentation, "Environmental Considerations for Paper and Printing." He also explains that the government's requirement for an ink to be labeled soy is a minimum of 7 percent soy. His estimations put most soy inks being used by web printers to be 3 percent soy and 60 percent petroleum, whereas sheetfed printers likely are using inks that are between 7 and 15 percent soy with 20 to 40 percent petroleum.
- Vegetable inks can be used on heatset and non-heatset presses, as well as sheetfed presses, according to MTRI. They also require no equipment changes.
- Dresser points out in his presentation that soy ink takes longer to dry, especially on heatset web presses. MTRI concurs, explaining this is "because vegetable inks penetrate paper more slowly and set primarily by oxidation." To speed up the drying or setting process for veggie inks, the institute reports, ink manufacturers add some petroleum oil. In particular, black soy-based inks take longer to dry than color soy-based inks.
- When selecting paper, a more absorbent stock can handle a higher percentage of vegetable oil, says MTRI.
- Some graphic designers prefer soy-based inks to those made with petroleum or linseed oil, MTRI notes, given that soy ink may offer better print quality and brighter colors.
- Be careful about pigments, drying compounds and additives in vegetable-based inks. MTRI points out that some of the more recent soy ink formulas use both non-toxic pigments and additives, but others could contain harmful substances in the pigments, drying compounds and additives.
To help marketers and print service providers more easily compare the range of ink products available today, the National Association of Printing Ink Manufacturers has developed a BRC Index, or a categorization of inks by their bio-derived content levels.