PRINTING TECHNOLOGY

Printing technology

The four processes that print almost all packaging, what separates them, and how to choose the right one for a job instead of the one the plant already owns.

The four processes that matter

Almost everything printed on packaging comes off one of four processes. They differ in how ink gets from the duct to the substrate, and that single difference decides the cost, the quality ceiling and the economic run length.

Process	How ink transfers	Image carrier	Typical packaging work
Offset	Indirect: plate to blanket to substrate, using the repulsion of oil and water	Aluminium plate	Folding cartons, labels, litho-laminated corrugated
Flexographic	Direct: anilox meters ink to a raised relief plate, plate touches substrate	Photopolymer plate on a sleeve or cylinder	Flexible packaging, labels, corrugated, paper bags, cups
Gravure	Direct: ink sits in engraved cells, doctor blade wipes the land, cells release ink	Engraved copper cylinder, chrome plated	Long-run flexible packaging, tobacco, decorative laminates
Digital	No image carrier: inkjet drops or toner placed under file control	None	Short runs, versioning, samples, late-stage customisation

A fifth, screen printing, still earns its place for heavy ink deposits, tactile varnishes and certain label effects, but it is a specialist step rather than a main process.

What actually decides the choice

In practice the decision comes down to four questions, asked in this order.

What is the substrate? A non-absorbent film narrows the field immediately. Gravure and flexo handle film comfortably; offset needs UV or special inks; digital depends heavily on the press and whether a primer is available.
How long is the run, and how often does it repeat? Gravure carries a high cylinder cost that only makes sense when it is spread across a long run or many repeats. Digital has almost no origination cost and a high cost per metre. Flexo and offset sit between them.
How many versions? Twenty SKUs of five thousand each is a different problem from one SKU of a hundred thousand, even though the total is the same.
What does the brand owner actually require? A tight brand colour on a metallised film is a harder constraint than a process image, and it can rule out a process on its own.

The common mistake is to answer question two first and stop there. Run length sets the economics, but substrate and colour requirement set whether the job can be produced at all.

Where the crossover points sit

There is no universal run length at which one process overtakes another. The crossover depends on origination cost, waste, machine rate and the number of versions, and all four differ from plant to plant.

What is reliable is the shape of the comparison. Digital starts cheap and climbs steadily. Gravure starts expensive and flattens out. Flexo and offset start moderately and climb gently. Where the lines cross for your plant is an arithmetic question, and it is worth doing with your own numbers rather than accepting a figure from a supplier presentation.

The running meter calculator and the ink coverage calculator give you two of the inputs. The rest come from your own cost sheet.

What limits quality on each process

Offset is limited mainly by ink and water balance. Once that is unstable, nothing downstream of it is stable either. Plate curves, blanket condition and dampening chemistry are where most offset colour problems actually live.
Flexographic printing is limited by the combination of anilox volume, plate screening and impression. Too much impression spreads the dot and the highlight detail disappears; too little and the solid goes patchy. The anilox calculator covers the volume side of that.
Gravure is limited by the engraving itself, because the cylinder cannot be adjusted once it is made. Ink viscosity and solvent balance are the day-to-day controls, and the doctor blade decides how clean the print is.
Digital is limited by the substrate interaction more than by the press. The head or engine is consistent; what varies is how the ink sits on the material, which is why digital still needs verification on the real substrate rather than on a test sheet.

Across all four, calibration is what makes results repeatable. That is the subject of G7 colour management.

Colour across processes

The reason a brand colour looks different on a carton, a pouch and a shrink sleeve is rarely that someone made a mistake. Each process has its own gamut, its own tone reproduction and its own substrate, and each one lands in a slightly different place.

There are two honest responses. Calibrate every process to a shared neutral appearance so the differences shrink to something a buyer accepts, which is what G7 is for. And set tolerances per substrate rather than one number for everything, because a tolerance a carton can hold is not one a metallised film can hold.

Measuring the gap is straightforward. The Delta E calculator gives you both the CIE76 and the CIEDE2000 figure, and explains why they disagree.

Frequently asked questions

Which printing process is best for packaging?

There is no single best process. Offset suits folding cartons and labels, flexo suits film, labels, corrugated and paper products, gravure suits long-run flexible packaging, and digital suits short runs and versioning. The substrate, the run length, the number of versions and the colour requirement decide it together.

What is the difference between flexo and gravure?

Flexo transfers ink from a raised relief plate that is inked by an anilox roll. Gravure transfers ink from cells engraved into a cylinder, wiped clean by a doctor blade. Gravure has a higher origination cost and holds long runs extremely consistently; flexo has a lower origination cost and more day-to-day adjustability.

Can digital printing match flexo or gravure quality?

On many substrates a modern digital press matches or beats them for image detail. The practical limits are substrate compatibility, cost per metre at longer runs, and reaching specific brand colours outside the press gamut, which affects every process, not just digital.

Why does the same file print differently on different presses?

Each process has a different gamut, tone reproduction and substrate interaction, and each press has its own condition. Calibrating every process to a common neutral appearance, which is the purpose of G7, is what brings them close enough to be acceptable.