What is the Most Sustainable Ink? | What Inks are Eco-Friendly
We often get the question: Are your inks soy-based? or Are your inks vegetable-based? or Are your inks water-based?
I believe what people are asking is: Are your inks eco-friendly?
The answer is complicated.
The truth is that there is no ink available today that is 100% free of non-renewable resources or chemicals. Algae Ink (available with a water-based and soy-based carrier) comes the closest. If you're printing in black, we strongly encourage you to ask for Algae Ink to keep you on the cutting edge of sustainable ink technology. Learn more about Algae Ink.
But we have come a long way since the 1970s. Inks contain a few different components: pigments (what gives the ink its color), additives (that improve performance, drying time, resistance to smudging, etc), and carriers (the vehicle that transfers the ink onto the substrate that then dries off, leaving only the pigment and additive behind). Carriers account for 70-80% of a bucket of ink. Pigments account for 10-20%, and additives account for 5-15%.
In the 1970s, most inks had petroleum-based carriers and were referred to as "solvent-based inks." When solvent dries, it releases volatile organic compounds in the air, which leads to poor air quality and adverse health effects for print workers. Petroleum-based inks also require print shops to use harsh cleaners on their printing plates and equipment, increasing the amount of VOCs emitted.
A combination of oil shortages and the EPA's Clean Air Act of 1970 led the printing industry to transition many historically solvent-based inks to vegetable/soy or water-based inks. These new inks featured carriers that were plant or water-based, though the additives and pigments largely remained the same.
In most cases, when soy or water-based inks dry, they emit very few (sometimes zero) VOCs. Print shops that have transitioned to soy or water-based inks typically report much better air quality and working conditions for their employees. It is also important to note that seeing a soy-based ink label does not necessarily mean that the carrier is 100% soy. Depending on the type of ink and its intended use, an ink’s oil content must be a minimum of 6% up to 40% soy to qualify for the Soy Seal logo. The mix of soy oil with petroleum oil would impact the level of VOCs emitted.
Choosing Between Inks Depends On Multiple Factors
There are a LOT of variables when it comes to printing.
First is the printing method, of which the most common are flexographic, offset, offset lithographic, digital toner, digital inkjet, screen printing.
The second is the printing substrate, which varies wildly. Uncoated paper and corrugate, coated paper and corrugate (which also ranges from clay-coated to plastic coated), plastic, glass, aluminum, cotton, wood, silk...the list goes on.
We believe it is valuable for eco-conscious companies to understand printing methods and the types of inks used within each printing methodology. Many thoughtful clients will ask, “are sustainable inks used”? We believe a more holistic and helpful question is, “can you tell me what printing methodology and printing inks will be used for my order?”
Digital means that an electronic image file is converted directly into the image, and the printer lays down dots and pixels to create the image you see on a screen. Digital printing is most often used for low-volume quantities though the definition of “low-volume” differs based on a print shop’s setup. In a diversified print shop, a run for a single art file of more than 10,000 or so units will result in the order shifting from a digital press to an analog press. Digital printing requires no real setup and allows for quick turns from one art file to the other.
Digital Dry Toner
This is similar to a toner printer you would have at home but, in most commercial establishments, would be done at a much larger scale. These printers use dry toners that are pigments encapsulated in resin (tiny plastic particles) instead of liquid ink. This pigment fuses onto the surface of the substrate using heat.
Despite the resin, toner printing is, in some ways, very eco-friendly because it emits no toxins into the environment and has a high-efficiency transfer rate. Very little waste is created, and there is no ink to discard at the end of the process. Almost all the pigment is used for artwork, whereas other printing inks have a carrier that evaporates during the process. Toner ink can be de-inked by recyclers and repulpers making it a suitable ink for products destined for recycling. Additionally, toner cartridges are typically collected by their manufacturers and reused.
Ink(s) used: Dry, digital toner pigments (no carrier).
Digital Liquid Toner
i.e. HP Indigo ElectroInk. This printer, which is becoming increasingly common in print shops, combines the concept of offset printing technology with digital toner technology. With the HP Indigo press, ink is transferred to a heated blanket which melts and blends the ink particles into a smooth film. The ink is then transferred to the facestock. The machine uses proprietary HP ElectroInk which contains charged pigmented particles encompassed in resin within a liquid carrier that is diluted with water or oil.
Ink(s) used: Resin encapsulated dry toner pigments immersed in a liquid carrier (water and/or oil).
Inkjet is a common form of home printing, but it is not used frequently for commercial printing. Ink sprays out from the printhead and absorbs into the facestock while some of the carrier evaporates. This printing method differs from toner, where pigments fuse into a facestock. Given this difference, inkjet printing may result in a slightly more faded look than toner.
Ink(s) used: Water-based pigment or dye inks.
Analog / Conventional Printing
Analog or conventional printing involves an electronic image file converted into a printing plate or screen. The printing press is set up with the plate or screen and the printing substrate. Ink is transferred to the plate and then onto the substrate. This type of printing typically produces higher-quality prints and closer color matching than digital printing.
Two types of analog printing, flexographic and offset, are extremely fast, making the per-unit cost lower than digital. However, the setup times are higher (often significantly high), making this printing less cost-effective for small runs. Screen printing is typically reserved for a small subset of orders that require extremely high quality and finish.
An image is converted into a flexible, photopolymer plate that is an exact mirror of one color of the printed image. This plate is wrapped around a printing cylinder. Ink is then transferred from the ink well, onto an anilox roller, and onto the printing plate, which then prints directly onto the substrate.
Flexographic printing on uncoated paper can utilize water-based or solvent-based inks. It is possible to use water-based ink when flexographically printing on coated surfaces or poly materials, but it can be challenging. In these instances, some print shops utilize UV curable ink, which does not contain any carrier because the ink is cured rather than dried.
Ink(s) used: Water or solvent-based inks. Additionally, innovative, eco-friendly inks such as Algae Inks are available, allowing for a renewable pigment.
Ink is transferred onto an aluminum printing plate, which prints the complete wet image onto a blanket, which then transfers the ink onto the substrate.
Offset printing on paper (the method used to print newspapers) can utilize solvent-based or soy-based inks. Since the 1970s, newspapers have been largely printed with soy-based carbon black ink.
Ink(s) used: Solvent, soy, or vegetable-based inks. Additionally, innovative, eco-friendly inks such as Algae Inks are available, allowing for a renewable pigment.
An image is burned onto a screen. Ink is placed on top of the screen and scraped down, letting ink transfer onto the substrate below only where the image has been burned onto the screen.
Screen printing inks can utilize solvent-based inks, soy-based inks, plastisol inks (which are cured inks), water-based inks (though water-based inks can be difficult to use), a decision that varies based on the substrate and drying/curing process.
Ink(s) used: Water-based, solvent-based, soy-based, or plastisol (cured) inks. Additionally, innovative, eco-friendly inks such as Algae Inks are available, allowing for a renewable pigment.
What to Ask and Look For When Considering Inks
If you do not know what kind of printing method your printing partner is using, we recommend asking this question: "Please share more information about your inks and what steps you've taken to make them eco-friendly?"
Alternatively, you might start the conversation by asking about the printing method and substrate being printed, to help you research sustainability considerations and the types of ink that you'd want to see used for your project.
Ultimately, look for ink with a carrier that is either water or soy / plants-based (deciding between the two will be dependent on the printing method and substrate) and that emits as few VOCs as possible.
Some companies have ink options and can help you understand the functional and sustainable pros and cons of their options. Other companies (like us) have specific inks identified for different use cases. Your print shop can then explain what kind of printing method they utilize, what kind of ink is being used for your specific project, and why it has been chosen.
Our Comprehensive Bill of Materials provides extensive detail on the ink types used for both inline and post-production printing on our various lines of sustainable packaging. But, in almost all of our printing, we use some type of low or no VOC water-based ink. The two main exceptions are the EcoEnclose logo on our Paper Apparel Mailers and our We Care Cards, which are both run through an offset press and utilize low VOC soy-based inks.
Printing Inks Used At EcoEnclose
Most products have a designated “inline printing ink” and “post-production printing ink.”
Inline printing refer to printing that takes place while an item is being manufactured and formed. Many EcoEnclose mailers are inline printed with our logo and recycled / recyclable information. Products ordered at large volumes may have the option of printing inline, which opens up the doors to a wider set of printing capabilities. Learn more about our Enterprise-Level Capabilities here.
On the other hand, post-production printing inks refer to when a mailer is printed after it has been formed. Most custom branded products ordered at lower volumes are printed post-production.
This table recaps the printing inks used for our post-production custom printed products. Note the ink used may differ from the information listed in this table based on the printing method for your particular order. If you have any questions regarding the printing method and ink used for your order, we encourage you to contact us.
|Poly Bags||Inline printing only (solvent-based)|
|Glassine Paper Bags||Water-based|
|Kraft Flatback Tape||Water-based|
|EcoBand Paper Product Wrap||Toner|
|Stickers & Labels||Toner or UV|
The Transition to Algae Ink
All of this discussion around soy and water-based inks deals with the ink's carrier alone.
Our Algae Ink, developed by Living Ink Technologies, is one of the first real innovations in the ink industry in the past few decades.
Instead of petroleum being used as the basis for the black pigment (the vast majority of black printer ink is carbon black, derived from fossil fuels), Algae Ink's pigment is derived from renewable algae cells (that are a waste product from an algae biofuel operation).
Water-based black Algae Ink is available for all of our paper and corrugate-based products - shipping boxes, paper mailers, notecards, paper shoppers, retail tuck boxes, and more. If you are looking for the most eco-friendly printing ink out there, we encourage you to explore algae ink.