Is Inkjet Environmentally Unfriendly?

By Ralf Schlozer / Published:

The focus on sustainability is gathering steam among consumers, print buyers and other organisations involved. Essentially this is a good and necessary move. The more surprising it is to see digital printing, specifically inkjet, being labelled not environmentally friendly by an organisation like Royal Mail.

Royal Mail Revising the Environmental Guidance

The latest version of the Royal Mail environmental guidance came into effect on the 4th of January 2022. The guidance sets out a series of dos and don’ts to encourage customers to create products that are environmentally friendly and socially acceptable. From using consent-based address databases, best practices in wrapping, usage of films and foils, sustainable sourcing of paper (Paper used in envelopes and wraps needs to come from certified sources and from a mill with a recognised environmental management system), the recyclability of items mailed is a major focus.

The new guidance replaces the sustainable advertising mail scheme which offered discounts to mailed items that complied with the environmental guidelines, extending this to subscriptions and publishing discounts. Ultimately the Royal Mail might withdraw discounts from mailed items that do not comply with the new guidance.

When the first environmental guidelines were released mid 2021 the Royal Mail stated that “it is not mandating for customers to adopt the specifications within the guidance, as they are optional. However, customers must continue to follow the existing Responsible Mail specifications to qualify for the discounted mailing rate” (which replaced a separate product termed Responsible Mail that offered the lowest mailing rates before).

The full text of the environmental guidelines can be found here

The relevant portion on inks used are:

“5. Ink:
a. Water soluble varnishes are permitted as are de-inkable
b. Other readily de-inkable inks are permitted
c. Inks which cause ‘red sock syndrome’ cannot be used for example; water based flexo inks, inkjet inks and inks using water soluble dyes or pigments unless evidence can be provided that they can be de-inked in standard de-inking plants.”

Royal Mail adds as further clarification: “Most literature produced in Europe is litho printed, de-inking plants were designed for de-inking litho. This process works well for gravure print. Magazines are fine, even with digitally printed address label or paper wrap and inserts, in the de-inking system. There are some water-based inkjet inks and UV cured that can be de-inked in standard de-inking plants and have been tested and certified as such”

The provisions apply to business mail, advertising mail (including partially addressed) and publishing subscription mail – in other words to pretty much all print transported by the Royal Mail.

What Does it Mean for Inkjet?

The environmental guidelines can be a bit confusing to customers and suppliers.

Unfortunately, clauses b) and c) can be somewhat at odds. A water-based ink can be de-inkable even if it causes bleeding (red sock syndrome) when appropriate bleaching steps are included. Likewise inks not prone to bleeding can be not de-inkable when they do not meet other de-inking parameters. For example, UV inks do not bleed but can be problematic.

In general, the de-inking situation is less clear cut as it sounds. As a proxy to de-inkability INGEDEs Method 11 test is used. INGEDE is the international association of the de-inking industry. Method 11 is a lab test designed to simulate de-inkability with small samples. Obviously, it cannot replicate all conditions in a full-blown de-inking plant, moreover conditions in existing de-inking plants tend to differ. As INGEDE cites on their website, although based on somewhat older findings, some inkjet prints are well de-inkable, while some are not. Besides judging de-inkability is a threshold process, in which several factors are considered on how well a given ink and paper combination needs to perform.

What Inkjet Vendors Say

I asked several inkjet press vendors with a strong presence in direct mail printing. Canon, Ricoh and Screen got back to me in time.

All vendors agree that there is no straightforward answer on inkjet being de-inkable and how representative lab tests as Method 11 are. There are some indications that prints from sheetfed devices do better than from continuous feed, coated works better than uncoated paper and primer increases the performance as well. Also, newer generation inks improve on de-inkability as their aim is to keep pigments on the top of the paper. What is aimed at making prints colorful and bright helps in de-inking as well. All vendors getting back to me had successful tests on de-inkability with their devices, however there is simply no way to test all paper and ink combinations and print conditions.

Ricoh states: “All Ricoh colour and mono sheetfed solutions are registered as de-inkable with INGEDE. We continue to test new inks and grades as and when they become market available. With inkjet we have had varied results using the specific approach chosen by INGEDE and those results – like any inkjet supplier – differ according to the specific ink being used, the individual substrate, the amount of ink coverage and whether an undercoat is applied.”

Further Ricoh adds: “de-inking is a complex subject and any answer needs to take into account the wide range of variables as mentioned above as well as the fact that the industrial recycling industry uses different recycling technologies and some of these enhanced approaches deal with inkjet material much better than others.”

Canon clarifies as well that prints produced using water soluble dye inks are normally not flotation de-inkable, however studies by Canon and independent institutes show that dye inks are often bleachable. This process step is not included in the laboratory de-inkability test of INGEDE Method 11 as not all de-inking mills utilize bleaching in their de-inking plants. Prints produced using pigment inks without primer/ColorGrip are sometimes flotation de-inkable and sometimes not, depending on the ink-paper combination. Prints produced using water-based pigment inks with primer/ColorGrip are almost always very well flotation de-inkable. In testing, Canon found that there are offset ink – paper combinations that fail the method 11 de-inking test as well. Newer generations of pigment inks such as the Chromera inks and the ProStream inks generally provide good to excellent de-inkability, even on standard uncoated papers, especially with the use of ColorGrip.

Adding to the de-inkability, vendors found that dye-based inks, the cause of the above mentioned “red sock syndrome” are rarely being used in Europe and Asia. The base is much larger in the US, although there is move to pigment inks in the US as well.


De-inking is a complex matter and it is no surprise that not too many discussions are held on this topic. The small share of inkjet in collected paper made it a secondary consideration, however with increasing inkjet volumes this is about change.

The Royal Mail is the largest postal service provider in the UK. Decisions by the Royal Mail do have strong implications on the UK direct mail market. Furthermore, they set a precedent for other delivery service providers around the world. Those are likely to focus more on sustainability in the future as well. De-inkability has been included in various European Eco-labels already, but an adoption by a major postal service providers has a much stronger impact.

Inkjet is not the only technology singled out. According to PrintBusiness, HP Indigo has been in contact with Royal Mail on HP Indigo ElectroInk being on the original exclusion list. It seems this has been fruitful as the exclusion of HP Indigo prints was deleted in a revision dated from the 12th of January. This proves that discussions between vendors and stakeholders can be fruitful. Inkjet vendors and printers should engage in that discussion to counter notions of inkjet not being environmentally friendly.


PS: as the discussion continues, I will look at general de-inking consideration in an article later this year.

About the Author

Ralf Schlozer

Ralf Schlozer is Independent Print Analyst. Ralf provides analysis, sizing and forecasting the market for digital printing technologies and associated applications and business processes. Connect with Ralf on LinkedIn

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