The Lowdown on Soy-Based Inks February 03, 2009 16:21 by John Sollars

If you’re interested in green printing, chances are you’ve heard of soy-based inks. They’re touted as the solution to environmentally unfriendly printing practices. While they are much more ecologically sound than traditional commercial inks, which are petroleum-based, they’re not perfect. Here are the facts about soy-based ink.

It’s better for the environment. Traditional commercial ink uses petroleum as the medium for suspended pigmentation. Petroleum-based inks start doing damage long before they’re thrown away—from the minute they’re laid down on paper, they release volatile organic compounds (VOC’s) into the air. These chemicals contribute to global warming and the indoor air pollution in your house and office. They also harm the environment when they decompose, releasing toxic chemicals into waterways and the atmosphere.

Soy-based inks are made from vegetable oils, which don’t release harmful chemicals when they decompose and dry. In addition, some proponents claim these inks are easier than petroleum-based inks to strip from paper during the recycling process, making recycling paper easier and more cost-efficient. Soy inks aren’t perfect, though—some still contain a small percentage of petroleum, and many reds and metallic colours contain heavy metals including zinc, copper and barium—which pollute the environment when disposed of. And most soy-based inks still contain waxes and other chemical additives that don’t significantly reduce their impact on the environment when disposed of in landfills. Still, they do release significantly fewer VOC’s than petroleum-based inks.

It comes in brighter colours. Soy-based inks are known for their vibrant colours. The vegetable oil medium used to suspend the pigments is clearer than petroleum, so colouring is better able to show through.

It can’t be used in personal printers. As of yet, there are no personal printers that use soy-based ink cartridges. Typically, soy inks are used by environmentally conscious printing companies. You can make a positive environmental impact by choosing a printing company that relies on soy-based inks, or by requesting that your printer use them in your project. Typically your printer shouldn’t have to use special printing equipment along with soy-based inks, so this should be possible for most printers using the equipment they have.

It costs a little more—but it’s more efficient. Using soy inks costs approximately 10% to 50% more than using traditional petroleum-based ink, depending on who you ask. However, this cost is offset by the fact that soy inks spread about 15% more than traditional inks—so less ink covers a wider surface. In addition, because the colours tend to be brighter, printers need less ink to produce more colour—reducing the amount of ink used per page even further. Essentially you can print more volume with less ink when it comes to soy.

It’s not usable for every medium. The one problem with soy-based inks is that it takes longer to dry than traditional commercial ink. This can cause problems when you’re printing on glossy rather than porous surfaces—approximately 90% of newspapers in the United States use soy-based inks, for example, but the magazine industry has yet to catch up because of the longer drying time. Some companies are experimenting with UV-reactive ink curing to encourage quicker drying, but this technique requires printers to invest in new technology, and it hasn’t been scaled down for mass production yet—so demand for it isn’t yet high.

Soy isn’t the only eco-friendly ink. In addition to soy, there are environmentally friendly inks available made from linseed and other vegetable oils. These oils are typically just as environmentally friendly and high-quality as soy inks, although their use isn’t as widely known as soy-based inks. Some printers blend soy inks with inks created from other vegetable oils to produce specific effects. Because of this, it’s often more accurate to ask for “low-VOC” printer ink instead of soy-based inks when looking into printers or ordering a print run.

It’s true that soy inks are more environmentally friendly than traditional petroleum-based inks. But while soy inks emit drastically less VOC’s, they are not necessarily completely biodegradable. They don’t evaporate well off glossy surfaces; they mainly dry via absorption, so if you’re printing on glossy paper you may not be able to use these inks. In addition, you can’t get soy-based cartridges for home use—you have to go through a printer.

Still, soy-based inks are becoming more and more popular with printers and businesses that care about the environment. If you want to make an ecological difference, ask your printer for soy-based or low-VOC inks.