Advice

Ask Lumi: Does Soy Ink Actually Make a Difference?

By Ian Montgomery · January 9, 2020

By volume, ink isn’t a huge part of packaging, but it uses high concentrations of VOCs and heavy metals which can sway the overall environmental impact of packaging.

The big picture. The easiest thing you can do to make your ink usage more sustainable is to use less of it. For example, opting for a positive print instead of a reverse flood coat could cut down on the amount of ink you use by over 75%.

Ink is made up of a few primary components, each one with more sustainable alternatives, but these alternatives often come with some material and machinery limitations in manufacturing. When you're choosing more sustainable options, be wary of greenwashing as ink does not have as many global certifications as materials like paper and compostable plastics.

The nitty gritty. Read on for answers to questions about ink and opportunities for sustainable alternatives.

  1. How much of an impact does ink actually have on the sustainability of my packaging?
  2. How is traditional ink harmful for the environment?
  3. How can I avoid VOCs?
  4. Are these solvent alternatives actually better for the environment?
  5. Can I use alternative inks with any manufacturer?
  6. What are pigments and how can I choose ones that are less toxic?
  7. Are there any colors I should avoid?
  8. What’s the problem with heavy metals?
  9. Is there any way to make resins and modifiers more sustainable?
  10. How does ink affect the recyclability or compostability of packaging?
  11. What materials can be printed with alternative inks?
  12. Do these alternative inks cost more than traditional inks?
  13. How do coatings affect the sustainability of my printed packaging?
  14. What certifications should I look for when it comes to ink?
  15. Are alternative inks a good investment overall?

1. How much of an impact does ink actually have on the sustainability of my packaging?

That depends on how much you’re using. On printed packaging, ink only makes up 1-3%, of the total weight — usually closer to 1% — but ink manufacturing is complex and can have negative implications on the environment.

Typically, ink is made up of approximately 35% resins and modifiers, 15% pigment, and 50% water or solvent. Within each of these areas, there are alternatives to improve ink’s environmental impact.

2. How is traditional ink harmful for the environment?

Solvents: The bulk of printing emissions come from solvents. These include butanol, ethanol, glycol ethers, heptane, hexane, methanol, mineral spirits, toluene, and xylene. The purpose of these solvents is to speed up the ink’s drying time.

Some solvents contain volatile organic compound (VOCs) which can be hazardous for human health and atmospheric pollution. According to the EPA, the printing industry ranks fifth in toxic volatile organic compound (VOC) emissions among major industries.

Pigments: In the past, pigments were loaded with toxic heavy metals including cadmium, arsenic, mercury, antimony, lead and selenium. For the most part, these metals have been phased out of traditional printing inks, but heavy metals are still found in paper sludge from recycled cardboard, predominantly from the pigments in ink.

Resins/Modifiers: Resins (often called vehicles or binders) add viscosity, so that the ink can properly flow through the printing press. Traditionally, these resins are derived from tall oil rosin — a byproduct of wood pulp — however synthetic resins are also used. Other modifiers are added to improve certain qualities in the inks like reducing surface tension, preventing degradation, and improving the ink’s ability to bind to particular surfaces.

3. How can I avoid VOCs?

Low-VOC printing with water-based, soy-based, or vegetable-based solvents is a good way to cut down VOCs. No-VOC options are available, but there are less factories that work with them.

Low-VOC options use safer chemicals to replace isopropyl alcohol (used for reducing the surface tension of ink) as well as alternatives to common chemicals used as laminates and adhesives. These options work best with paper surfaces, but can present challenges on plastic or other non-porous surfaces due to issues with bonding, absorption, and drying time.

UV (ultraviolet)-cured inks dry using UV light to dry ink, instead of heat and air. Traditional heat-and-air drying releases VOCs into the air, while UV cured inks don't need solvents and instead rely on a mix of liquid monomers, ligomers, and photoinitiators which, under UV light, create a photochemical reaction. The ink dries instantly without releasing any VOCs. It's worth noting that UV curing can be energy intensive.

4. Are these solvent alternatives actually better for the environment?

Yes. Low-VOC inks are better for air quality and the health of print industry workers. However it is worth noting that the soy ink label is often misleading, as an ink only needs to be a small percentage of soy oil — as low as 7% — to be considered soy-based. Thus, many inks labeled with the soy ink seal do not avoid the VOC problem.

VOCs aren’t only found in the ink. They can also be used in processes like print plate cleaning, though more low-VOC options for the plate and ink clean-up are becoming available.

New developments with algae-based inks have recently come to market as another non-toxic ink alternative. Algae ink is free of petroleum and it sequesters carbon.

5. Can I use alternative inks with any manufacturer?

Many collateral printers are set up to regularly run soy and other alternative inks, but for corrugated and plastic printing, the process is often a bit more complicated. Some machines that run traditional inks, like water-based, can run alternative inks, but it requires some machine down time to thoroughly clean the machine and dial it in to accommodate a new ink with a different viscosity or drying time.

As alternative inks become more prominent, more manufacturers are adapting to accommodate them more easily. If you are looking for a manufacturer that is specifically set up for alternative inks, you can request this when sourcing packaging with Lumi.

6. How can I choose pigments that are less toxic?

Pigments are the concentrated powders that give ink its color. They can be derived from minerals or made synthetically. Before the mid-70s, many of the vibrant pigments in inks were made using relatively high levels of heavy metals like cadmium, arsenic, mercury, antimony, lead, and selenium. Starting in the 1970s, a series of domestic environmental regulations — like the Coalition of Northeastern Governers' Toxics in Packaging Clearinghouse and Europe's packaging waste directive 94/62/EC — began phasing out high levels of heavy metals from conventional printing inks.

Recent studies have found traces of heavy metals in recycled corrugated cardboard, predominantly from pigments. But further studies looking at the heavy metal content, specifically in newspaper sludge, have determined that pigments used in news inks have low acute toxicity and are not carcinogenic or mutagenic. Carbon black, the pigment that goes into nearly all black ink, is listed as a carcinogen when airborne in California , but if it’s coated in another material like resin, it’s not considered carcinogenic.

The following are some of the current regulations that impact the pigment industry in the US: the Resource and Conservation Recovery Act, the Clean Water Act, and the 1986 Superfund Amendments and Reauthorization Act Title III.

Barium and Copper in Select PMS Ink Colors (in parts per million)

7. Are there any colors I should avoid?

There are strategies designers can use when thinking about ink usage. It goes without saying that using more ink is less sustainable than using less ink. While spot printing allows for exact and vibrant color matching, spot colors have a higher risk of containing heavy metals than process (CMYK) colors. However it should be noted that cyan — the C of CMYK — can contain copper.

Certain colors and effects should be automatic red flags. In general, big ink companies in Europe are pushing hard to make blues with low enough levels of copper to pass the stringent European compostability tests on their own. Reds and yellows can contain high levels of cadmium and barium as well. These colors certainly shouldn’t be avoided altogether, but check with your printer about metal content of the pigments involved, and if applicable, perform a verified compostability test.

At a high level, here are the metals in various colors:

  • Reds risk containing cadmium and barium
  • Yellows risk containing cadmium and barium
  • Whites risk containing zinc and lead
  • Metallic inks risk high levels of copper and zinc
  • Blues risk container copper

8. What’s the problem with heavy metals?

At deinking facilities where recycled paper is processed, the heavy metals in inks can form a sludge which will be landfilled or incinerated. One major concern is that those metals can leak into ground water, which could lead to a serious health issues in both humans and wildlife.

Neurological damage is the most serious risk heavy metals may have on health, although some compounds have also shown to be carcinogenic, aggravate asthma, decrease sexual potency, and contribute to birth defects. Toxic metals in pigments, especially when combined with hazardous VOCs in ink solvent, lead to particularly hazardous work environment for print industry workers.

9. Is there any way to make resins and modifiers more sustainable?
Resins and modifiers don’t have a significant environmental impact. They are traditionally fossil fuel based, though more are becoming available with some percentage of biobased materials. The term biobased product was legally defined in 2002 as a product (not food or feed) that is predominantly or entirely made from plant, animal, or marine materials.

This list from Ink Intelligence gives a good breakdown of biobased alternatives to ink components. If the information is available, look for inks with a high BRC (biorenewable content) score.

10. How does ink affect the recyclability or compostability of packaging?

Ink will not affect the recyclability of a package. Recyclability depends on the substrate the ink is printed on. During paper recycling, deinking occurs to separate ink from the paper pulp. The pulp is used to make new paper products while the de-inked sludge is either landfilled or incinerated.

As for composting, because ink is typically such a small percentage of a package, it may not even be counted in compostability tests. In US ASTM D6400 biodegradability tests, ingredients that take up less than 1% of the item do not need to be tested individually. As ink flirts at that 1% threshold of a package, the ink itself doesn’t technically need to be compostable to meet US Compostability standards. However this shouldn’t be a free pass to print with potentially hazardous inks. Some ink suppliers have managed to make many of their ink lines and colors meet the OK Home Compost standard.

11. What materials can be printed with alternative inks?

Paper can be printed with nearly any type of ink, but plastic is a bit more finicky. The main reason is that plastic is less porous, so getting the ink to bond, absorb, and dry requires different processes. If you’d like to use alternative inks on plastic, we can work with you to find the right ink based on your design and location requirements. 

To avoid plastic altogether, consider plastic-free products.

12. Do these alternative inks cost more than traditional inks?

Because factory availability is limited and they typically take a bit more time to work with, alternative inks can cost significantly more than traditional inks. But since ink is such a small fraction of the overall volume of your packaging, the cost increase per item is relatively small. Of course, to cut down on ink costs, you can design your packaging to use less of it.

13. How do coatings affect the sustainability of my printed packaging?

UV ink is cured with radiation so that the toxic solvents aren’t evaporated into the air. The downsides of UV printing are the higher cost and the high energy consumption.

Aqueous coating does not affect sustainability as it's mostly water-based.

14. What certifications should I look for when it comes to ink?

Unfortunately there are no standard certifications to look for, however there are a few organizations and certifications to be aware of.

In the US, the National Association of Printing Ink Manufacturers assigns a Biorenewable Content number (BRC) to an ink. This number indicates how much of a given ink is sourced from bio-based resources. For example, a BRC 50 ink contains 50% bio-based components. If you want to know the BRC index of available inks, we can request this information from factories in the Lumi network.

Also here in the US, the Sustainable Green Printing Partnership has guidelines that form a good rubric for domestic printers, however their certification program is still growing so it’s certainly not a red flag if your printer isn’t certified SGGP.

15. Are alternative inks a good investment overall?

If a more alternative ink is available for the same cost, that’s ideal. But if you’re looking for ways to make your packaging more sustainable, we suggest starting with the Lumi Sustainability Properties.

Pick the top three priorities for your company and rank them. If alternative inks don’t land in your top three priorities, you may be better off finding ways to optimize your top priorities and use your packaging spend in those areas first.


Do you have more questions about sustainable inks? Tweet @Lumi with the hashtag #asklumi

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