Short answer
Because every extra ink needs its own printing unit, its own wash-up and its own make-ready, and those are costs per job, not per copy. The EU's reference document for solvent-using industries, which covers printing, lists special colours and changes of colour sequence among the things that raise consumption per unit printed, and describes a packaging plant that stopped cleaning seven of its eight units between jobs by building colours from seven standard inks. No public source prices a spot ink or a wash-up, so the mechanisms are documented and the money is not.
A press lays down one ink per printing unit. Four units print cyan, magenta, yellow and black, and any colour that is to be printed as its own ink needs a fifth. The EU reference document describes this for publication gravure: most presses have eight units, four for each side of the web, and occasionally a fifth unit per side is added, ten in all, to allow a spot colour such as a metallic or fluorescent ink for special effects. After each colour the web passes through a dryer before the next unit. A spot colour therefore costs a unit that has to exist on the press, a cylinder or plate for that job, an ink that has to be mixed or bought for it, and a dryer pass. On a press with no spare unit the job cannot run at all. The print section explains what a spot colour buys in return: colours outside the process gamut, and solids that do not depend on four inks staying in balance.
The larger cost is in changing over. For heatset web offset the reference document says specific consumption and emissions increase with decreasing print volume and with increasing use of special colours or a change of colour sequence; for flexible packaging it gives the same list with 'increasing number of colour change sequences'. A unit that carried one job's special ink has to be washed before the next, and the press then runs waste until colour and register are right. The document's model heatset plant shows where that waste sits. It buys 20,000 tonnes of paper and 500 tonnes of ink a year and loses 2,800 tonnes as paper waste and misprints, against six tonnes of ink residue. Ink is a small part of what a printer buys, and paper spoiled while colour is brought up is a large part of what it throws away. The paper figure covers all waste, not only colour-related make-ready.
The industry's answer is to stop changing inks. The reference document describes a Dutch UV flexographic plant where cleaning between packaging jobs had become prohibitively time-consuming. It adopted a system that builds the required colours from seven standard inks, so that seven of eight units need no cleaning between jobs and the eighth is kept for an additional colour if one is still needed. The document adds the limit: four standard colours, as used for photographs in publications, cannot produce every colour and brightness packaging needs. Seven-colour printing with orange, green and violet added to the process set is the current form of the idea. A peer-reviewed trial on a narrow-web flexographic press found that how accurately such a set reproduces chosen spot colours depends on how the press was characterised: each of two software systems did better with its own test chart than with a shared one. The saving in wash-ups is bought with characterisation work and a tolerance on brand colours.
Ink used rises with the area covered. The reference document lists 'increase in surface to cover' among the drivers of consumption and emissions in flexible-packaging printing, alongside short runs and frequent colour changes. That is the whole of what the public record says in general terms, and it is a direction, not a tariff: no source reviewed here gives a cost per square metre of solid colour or per percentage point of coverage. The consequences are well known to anyone who has specified packaging. A design with a flood-coated background uses more ink and more drying than one printed on white, and a design that needs white ink under its colours on clear film or metallised board adds a further ink and unit. The print section's page on total ink coverage deals with the separate, technical limit on how much ink a sheet can carry.
White is the one ink colour with a public economic record, because of a trade case. When the EU imposed anti-dumping duties on Chinese titanium dioxide in January 2025, of 0.25 to 0.74 euros a kilogram, three ink makers asked for an exemption for the grade used in white printing inks. The Commission found that only a very limited number of producers worldwide make that grade to the required quality, one of them in the EU, that white-ink producers account for around 2.5% of the EU titanium dioxide market, and that the duties would have made one applicant loss-making in its white-ink business. It granted the exemption. One ink maker showed that over 99% of the titanium dioxide it buys goes into white inks. So the cost of the white under a printed pack depends on a narrow, specialised pigment supply, and regulators treated it as a case apart.
| What it concerns | Colour or finish factor | Published figure | Where and when | Kind of evidence |
|---|---|---|---|---|
| Flexible-packaging printing (flexography and gravure) | Area of the design covered with ink | No figure published | European Union; Information exchange to 2018; published 2020 | Documented industry practice |
| Model heatset web offset plant | Ink as a share of what the plant buys | 500 tonnes of ink a year, against 20,000 tonnes of paper | European Union; 2004 model plant, published 2020 | Measured cost |
| Model heatset web offset plant | Paper lost as misprints and make-ready | 2,800 tonnes of paper and misprints a year, of 20,000 bought | European Union; 2004 model plant, published 2020 | Measured cost |
| Publication rotogravure | A spot colour such as a metallic or fluorescent ink | 5 printing units per side, against four for process colour | European Union; 2016 industry information, published 2020 | Documented industry practice |
| Heatset web offset | Special colours and changes of colour sequence | No figure published | European Union; 2004 working-group information, published 2020 | Documented industry practice |
| UV flexographic packaging printing | A fixed set of standard inks in place of job-specific colours | 7 of eight printing units not cleaned between jobs | Netherlands; Reported 2009, published 2020 | Documented industry practice |
| Seven-colour (CMYK plus orange, green, violet) flexographic label printing | Spot colours reproduced from a fixed ink set | No figure published | Toronto, Canada; 2022 | Documented industry practice |
| Factor | How it becomes cost | What the record leaves out |
|---|---|---|
| Area of the design covered with ink | Specific ink and solvent consumption, and emissions, increase with the surface to be covered. | A direction of effect; no cost per square metre or per percentage point of coverage. |
| Ink as a share of what the plant buys | Ink is a small tonnage beside paper, so the material cost of colour in publication printing sits mostly in the paper spoiled while colour is brought up. | A constructed reference plant, not a measured one; the conclusion about where cost sits is Colourwise's reading of the tonnages. |
| Paper lost as misprints and make-ready | Paper printed before colour and register are right is waste; the model plant loses far more paper this way than it loses ink. | Covers all paper waste, including trim and web breaks, not only waste caused by colour. |
| A spot colour such as a metallic or fluorescent ink | Each colour needs its own printing unit and dryer pass, so a spot colour means a fifth unit per side on a press built for four process colours. | Described as occasional; no cost for the extra unit is given. |
| Special colours and changes of colour sequence | Specific consumption and emissions increase with the use of special colours or a changed colour sequence, since each brings wash-ups and make-ready. | A direction of effect listed among several drivers; not quantified. |
| A fixed set of standard inks in place of job-specific colours | Building job colours from seven standard inks means most units keep the same ink from job to job and need no cleaning between them. | One plant's patented system; the same passage notes that four standard colours cannot produce every packaging colour. |
| Spot colours reproduced from a fixed ink set | A fixed seven-ink set can stand in for many spot inks, but how closely depends on how the press was characterised: each software did better with its own test chart than with a shared one. | Only the abstract was read, so no colour-difference figures are recorded; one press and substrate. |
Why: The ink is minor; the unit, the wash-up and the make-ready waste are the cost.
Fix: Ask the printer what the extra colour adds per job and how many units the press has free.
Why: A fixed ink set reproduces many spot colours within a tolerance, and accuracy depends on the press characterisation.
Fix: Have the specific brand colours proofed on the intended press and substrate, with the tolerance agreed first.
Why: White is an ink and a unit like any other, and often the heaviest coverage.
Fix: Count white as a colour when comparing designs and quotations.
Each statement is labelled by kind — established fact, a standard’s requirement, observed market data, a convention, or Colourwise’s own interpretation or analysis — with the strength of the evidence behind it.
FactStrong evidence
The EU reference document states that most publication gravure presses have eight printing units, four process colours per side, and that occasionally a fifth unit per side is included to allow a spot colour such as a metallic or fluorescent ink.
Caveat: Describes publication gravure in Europe from 2016 industry information.
FactStrong evidence
The same document says specific consumption and emissions in heatset web offset increase with decreasing print volume and with increasing use of special colours or changes of colour sequence.
Caveat: A stated direction of effect; the document does not quantify it.
FactModerate evidence
A Dutch UV flexographic packaging plant described in the document builds its colours from seven standard inks so that seven of eight printing units need no cleaning between jobs.
Caveat: One plant's patented system, reported in 2009; the document does not give the saving in time or money.
FactModerate evidence
In a trial on a narrow-web flexographic press, two expanded-gamut software systems each reproduced selected spot colours more accurately from their own characterisation charts than from a shared industry chart.
Caveat: Only the abstract was read, so no colour-difference figures are given; one press, ink system and substrate.
Source: Accuracy of spot color reproduction in a 7-color, expanded gamut, flexographic printing system
StandardStrong evidence· Regulation of 17 December 2024, in force January 2025
The European Commission estimated that white-ink producers account for around 2.5% of the EU titanium dioxide market and exempted pigment used for white printing inks from the anti-dumping duties of 0.25 to 0.74 euros a kilogram imposed on Chinese titanium dioxide in January 2025.
Caveat: The exemption is conditional on end use, and trade measures are reviewed; current status should be checked.
Colourwise interpretationLimited evidence
The cost of a spot colour is mainly a cost per job (a unit, a wash-up, a make-ready), which is why it weighs on short runs and almost disappears on long ones.
Based on: Colourwise's reading of the EU reference document's list of consumption drivers, its model heatset plant and the fixed-ink-set case, as recorded in the observation dataset.
Caveat: No source prices a wash-up or a spot ink, so the split cannot be put in numbers.
Reviewed 6 October 2026. Colourwise summarises its sources in its own words and does not reproduce standards text or proprietary colour data. Spotted an error? Tell us.