Technologies
Colour Matching
Instrument-led matching to a measured standard, on your own substrate, with the tolerance and the light fastness stated rather than implied.
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The technology
Colour Matching
A colour match is an agreement about three things: a standard, a measurement condition and a tolerance. Without all three, “matched” means whichever of us is holding the drawdown. We measure the target, predict the formulation from our pigment database, print a drawdown on your substrate at your film weight, and correct against the measured difference until the match sits inside an agreed tolerance under a stated condition.
The substrate is part of the colour. The same ink reads differently on kraft, on coated board, on white film and on clear film over a product, because the substrate contributes reflectance, opacity and often optical brightener. A match made on a laboratory card and approved in a light booth will not hold on unbleached liner, and there is no recipe correction that fixes that — the drawdown has to be made on the material the job will run on.
Film weight is the other half. A colour is a pigment concentration through a thickness, so a match approved at a laboratory draw-down weight and run at a different anilox volume is a different colour. We match at the film weight the press will actually lay down and state it on the match report.
How it works
Measurement conditions, and why they are quoted
A spectrophotometer reading is only comparable with another reading taken the same way. We state the condition on every match report, because a difference in any one of these will move ΔE more than a formulation correction will.
- Geometry. 45°/0° or d/8°. The two do not agree on anything with gloss or texture.
- Illuminant and observer. D50 with the 2° observer for graphic arts work, D65 where the brand standard calls for it.
- Measurement mode. M1 (UV included, D50) on optically brightened stock, because an OBA-loaded paper fluoresces and M0 and M1 will disagree by several ΔE units on the same sample.
- Backing. Black or white backing to ISO 13655, declared, because on any substrate that is not fully opaque the backing is part of the reading.
Difference is reported as ΔE00 (CIEDE2000) rather than ΔEab, because CIEDE2000 corresponds far better to what the eye accepts, particularly in blues and in near-neutrals.
Choosing
Expanded gamut, spot colours and when to use which
An expanded-gamut set — CMYK plus orange, green and violet, matched to the Pantone Extended Gamut reference — builds spot colours from seven fixed inks. Nothing is washed up between jobs, several jobs gang on one forme, and inventory collapses to seven products. The cost is that a proportion of the Pantone book sits outside what seven process inks can reach, particularly the strong oranges, the fluorescents, the metallics and some deep blues, and that a screened build will never match the smoothness of a solid laid spot in a large flat area.
A made spot colour is the answer where the colour is a brand asset, where the area is large and flat, where opacity over a dark or clear substrate matters, or where the shade sits outside the achievable gamut. Most operations end up with both: expanded gamut for the volume and made spots for the two or three brand colours that carry the pack. We supply either, and we will tell you honestly which one your shade needs.
How a match is specified
| Standard | A measured standard, supplied as a physical sample, a Pantone or brand reference, or spectral data. A printed sample is preferred to a book reference, because a book is printed on its own paper with its own ink film and is itself an approximation of the brand colour. |
|---|---|
| Measurement geometry | 45°/0° or d/8°, stated on the report. Readings from the two geometries are not interchangeable on anything with gloss, metallic pigment or texture. |
| Illuminant and observer | D50 with the 2° standard observer for graphic arts work; D65 where the brand standard requires it. Stated on the report, because a metameric pair that matches under D50 can be visibly different under a shop’s fluorescent lighting. |
| Measurement mode | M0, M1 or M2 as appropriate; M1 (UV included) on optically brightened substrates. On OBA-loaded stock the difference between M0 and M1 readings of the same sample is routinely several ΔE units, so the mode is part of the specification, not a setting on the instrument. |
| Backing | Black or white backing to ISO 13655, declared. On film, on thin paper and on any partly opaque print, the backing changes the reading and therefore changes the match. |
| Tolerance | Typical commercial acceptance ΔE00 ≤ 2.0 against the approved standard, measured on the agreed substrate at the agreed film weight. Brand-critical colours are usually specified at ΔE00 ≤ 1.0, which is achievable but constrains substrate, film weight and press tolerance in return. |
| Substrate and film weight | The match is made on your substrate at your film weight and both are recorded on the match report. A change of substrate, of anilox volume or of coating is a new match, not a correction — which is why the record matters when a job is repeated a year later. |
| Light fastness | Stated per grade on the Blue Wool Scale to ISO 105-B02: typically BWS 3–4 for promotional and short-life work and BWS 7–8 for outdoor and long-life labels. This is pigment chemistry, not recipe: a shade that needs BWS 7 may be unreachable with the pigments that make the brightest version of it. |
| Opacity and substrate colour | Where the print sits on kraft, on a coloured substrate or on clear film, opacity is specified alongside shade — by an opaque white underprint, by a double hit, or by an opaque grade. A shade specified without an opacity statement will drift with every change in the substrate beneath it. |
| Batch control | Every production batch is measured against the retained master standard before release, with colour difference and strength recorded on the batch certificate. Tinting strength is held to ± 2 % of the master, because a batch that matches in shade but not in strength will not match on press at the same film weight. |
| What we need to start | The target (sample or data), the substrate, the process and film weight, the light condition the pack will be judged under, the light-fastness requirement and the tolerance you want to work to. A sample of the substrate with the request saves a round trip. |
Where it is used
Products and papers that build on this technology.
Screen Printing Inks
Matching across eight substrate series.
UV Flexo Inks
Expanded gamut to the Pantone reference.
Specialty and Effect Inks
Metallic, pearlescent and fluorescent shades.
Contact technical service
Send a target and a substrate and we will match it.
Questions we are asked
The things that decide whether a match holds on press.
It matched in the light booth and not on the shop floor
Metamerism: two colours built from different pigments match under one illuminant and differ under another. Tell us the light the pack will be judged under and we will match under it, and where the standard and the substrate allow, build the match from a pigment set close to the original so the pair is less metameric. A match approved under only one illuminant carries this risk by construction.
Our ΔE looks fine but the customer rejects it
Check what ΔE is being quoted. ΔEab and ΔE00 are different numbers for the same pair, and they disagree most in exactly the blues and near-neutrals where rejections happen. Check the measurement mode and backing too: an M0 reading on brightened stock will not agree with the customer’s M1 reading of the same sheet.
The colour drifts through the run
Almost always laydown rather than ink. On flexo, a worn or plugged anilox loses volume and the colour goes weak at unchanged viscosity; on water-based work, a falling pH does the same. Measure the anilox, hold the pH, and control viscosity at press temperature. Only then look at the ink.
Can you match a metallic, a fluorescent or a pearl?
Yes, and they are specified differently. Metallic and pearlescent shades are geometry-dependent, so they are agreed on a physical sample and a stated viewing geometry rather than on a single spectrophotometer number. Fluorescents have low light fastness by nature — typically BWS 2–4 — and that is stated up front rather than discovered on a window display.
How long do you keep the standard?
The retained master and the match record — substrate, film weight, measurement condition, tolerance and batch data — are held so a repeat order a year later is made against the same reference rather than against a printed sample that has since aged in an office.
Should we move to expanded gamut?
It pays where the operation runs many short jobs with many spot colours, because the saving is in wash-ups and inventory rather than in ink price. It does not pay where a few brand colours dominate large flat areas, or where the shades sit outside a seven-ink gamut. Send us the colour list and the job profile and we will tell you which of your colours can be built and which have to stay as made spots.
Key points
Measured, not eyeballed
Spectral target, predicted formulation, corrected against a drawdown.
Conditions stated
Geometry, illuminant, mode, backing and tolerance on every match report.
Gamut or spot
Pantone Extended Gamut builds, or a made colour where the shade needs one.
Light fastness
Blue Wool to ISO 105-B02, stated per grade before the job runs.
Don't see what you're looking for?
Please feel free to call us. We colour-match to any request and develop inks around your press-room need.
Science Technology Innovation & Application. Printing inks and coatings for packaging, label and graphic printing since 2006.
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