Ink made from soy is often called vinegar ink or “soy tinta.” As inks go, it is perhaps the most earth-friendly as it takes minimal energy to produce the ink. Soy leaves minimal agricultural residues, does not need irrigation, and requires very little fixed nutrients. Unlike other dyes or inks, soy ink emits very little volatile organic compounds (VOCs) which are a major contributing factor to air pollution.
Soy ink was discovered in the 1970s when the Newspaper Association of America began looking for ink outside of the standard petroleum-based ink. They were looking for a cost-effective method and to get out of the struggles with oil-producing countries of that time. It took testing more than 2,000 vegetable oil formulas to come up with the soy-based ink that worked.
The National Soy Ink Information Center was soon founded to promote the use of this cost-effective ink that supported American soy farmers and helped preserve the environment. By 2005, nearly all of American’s newspapers had adopted the use of the ink, in addition to 25% of commercial printers, leading to the closing of the National Soy Ink Information Center, as it was no longer needed.
Soy ink biodegrades four times more effectively than petroleum-based inks. And when recycling papers, soy-ink is much more easily removed than other standard inks. And the waste made from de-inking soy inks is non-toxic and can be disposed of easily. As soy oil is clearer oil, it takes less pigmentation to color the oil and make it bright, reducing the cost of the ink and also aiding in recycling capabilities. Remarkably, soy ink also spreads 15% better than other inks, making it even more cost-efficient.
However, soy inks are not without disadvantages. Soy ink cannot be used in personal printers or ball-point pens. And because it emits less VOCs, that also means it evaporates more slowly, increasing drying time. This does make it more difficult for newspaper printers. However, with UV-reactive ink curing technology, many large printers are able to quickly dry the ink without emitting VOCs. But obviously this is not cost-effective for small printing needs.