What is soy ink?
Soy ink is an alternative to traditional petroleum-based ink. It has been around to some degree since the late 1970s, but the popularity has spiked considerably in recent years. The first industry to embrace soy ink was the newspaper industry.
One advantage to using soy ink is the availability of brighter colors. Another key factor is that soy ink, unlike its petroleum-based competition, is a renewable resource. Some soy-based inks also emit zero VOCs (volatile organic compounds). They are cleaner and more environmentally friendly because they release fewer emissions during the printing process. If you use soy-based ink it also makes it easy to recycle the paper after it's been used.
One disadvantage to using soy ink is the amount of time it takes to dry, though that is mainly due to the fact that it does not have the solvents from VOCs.