Corrugated Box Printing: Postprint, Preprint and Litho-Lamination Compared
Last updated: October 2026
Quick answer: Corrugated boxes are printed in three main ways: postprint flexo directly on combined board, preprint flexo on the liner reel before corrugating, and litho-lamination, where an offset-printed sheet is laminated onto the board. Postprint and preprint use photopolymer flexo plates; litho-lam uses offset CTP plates. The choice depends on graphics level, order volume and existing equipment.
Key takeaways
- Postprint flexo is the workhorse for shipping boxes; graphics are limited by the fluted board, not just the plate.
- Preprint gives near-packaging-quality print on the liner but needs large, stable order volumes.
- Litho-lamination delivers offset quality on boxes and uses aluminium offset plates, not flexo plates.
- We manufacture both the flexo plates and the offset plates used in these processes, plus offset plate processing equipment.
A box plant’s print requirements have changed. Plain brown shipping cases with one-colour logos still make up much of the volume, but supermarkets, e-commerce brands and appliance makers increasingly want boxes that also work as displays. Many box makers still believe boxes are brown transport packaging so plate quality hardly matters. Retail-ready and shelf-ready boxes are now part of the brand display, so plate choice and prepress decide whether they sell. This page explains corrugated box printing process by process, and which corrugated printing plates and prepress each one needs. For the corrugated flexo plate itself — gauges, hardness and fluting control — see our dedicated corrugated flexo plate page.
Three ways to print corrugated boxes
Corrugated printing is not one process with one kind of plate. Postprint, preprint and litho-lamination each use different plates and prepress, chosen by graphics level and order volume.
| Process | Where printing happens | Image carrier | Typical use |
|---|---|---|---|
| Corrugated postprint | On combined board, in a printer slotter, flexo folder gluer or rotary die-cutter | Thick, soft flexo plates on carrier sheets | Shipping cases, e-commerce boxes, simple retail boxes |
| Corrugated preprint | On the liner reel, on a wide-web flexo press, before the corrugator | Thinner flexo plates on sleeves or cylinders | High-graphic boxes in large, repeat volumes |
| Litho-lamination | On paper sheets in a sheetfed offset press, then laminated to board | Aluminium offset CTP plates | Premium display boxes, consumer electronics, toys |
Inkjet printing of boxes is also growing; it uses no plates and is outside our range.
Postprint flexo: printing on combined board
In corrugated postprint, the finished board is fed sheet by sheet through a printer slotter or a flexo folder gluer, which prints with water-based inks, slots, folds and glues in one pass. Because the plate prints on a fluted, compressible surface, the main plate issues are:
- Fluting (washboarding) — flute lines showing through solids. Plate softness, gauge, cushion and impression all play a part; the corrugated plate page covers this in detail.
- Board crush — too much impression reduces box strength, so plates must print at a light “kiss” impression.
- Rough recycled kraft liner — absorbent, uneven surfaces need plates and anilox settings that lay down ink evenly.
- Registration moves between colours on the folder gluer — often a mounting issue: plates mounted on carrier sheets must be positioned accurately and consistently.
Typical in the industry, postprint plates run in thick gauges such as 3.94 mm and 6.35 mm, with 2.84 mm for finer work on suitable presses. Older machines are not a dead end either: “our printer slotter is too old for fine print” is often partly a plate and mounting question, and a better-matched plate can lift print quality without buying a new press.
Preprint flexo: printing the liner before the corrugator
In corrugated preprint, the kraft liner or white top liner is printed on a wide-web flexo press, usually central impression, and rewound. The printed reel then runs through the corrugator as the outer liner. Because the liner is flat when printed, there is no fluting, and print quality approaches flexible packaging levels.
- Plates are thinner than postprint plates — typical in the industry, from 1.14 mm up to 2.84 mm depending on the press — and are usually digital for process-colour work.
- Repeat length and register must account for liner shrinkage through the corrugator.
- Preprint only makes sense for large, repeated volumes of the same design, because every order needs a full liner reel run and corrugator scheduling.
For preprint, our digital flexo plates imaged on a flexo CTP imager are the usual route. Flexo imagers and plate making machines are supplied with our partner factories; the plates are made in our factory.
Litho-lamination: offset printing for high-graphic boxes
Litho-lamination (litho-lam) prints the graphic on coated paper by sheetfed offset, then laminates it onto single-face or combined board. It gives the best image quality of the three, at a higher cost per box, and it is the reason some box plants also run an offset plate room.
- Plates: thermal CTP plates or CTcP plates; a bakeable double-layer thermal grade for long runs with UV inks.
- Formats are often B1 or larger, so the plate room needs a large-format platesetter (supplied with our partner factories).
- A plate processor, baking oven and pneumatic punch and bender from our factory complete the setup.
“Litho-lam is too expensive for our customers” is often true for transport boxes — but for display boxes the higher print quality is what the brand is paying for.
Choosing a corrugated printing process and plate setup
| Job need | Recommended plate type | Why |
|---|---|---|
| Shipping cases, 1–3 colours, many small orders | Analog or digital corrugated flexo plates, thick gauge | Low plate cost, light impression on board, fast changeover |
| Retail-ready boxes on postprint presses | Digital corrugated flexo plates | Sharper text, barcodes and halftones on fluted board |
| High-graphic boxes in large repeat volume | Digital flexo plates for preprint, thinner gauge | Flat liner, no fluting, near-packaging quality |
| Premium display boxes | Thermal CTP or CTcP offset plates for litho-lam | Offset image quality on the laminated top sheet |
If your plant has too many box designs with small orders, postprint with well-made plates stays the most economical. If customers want better graphics without buying a new press, start by reviewing plates, mounting and anilox on the existing postprint line. For a general comparison of plate families, see the plate selection guide.
What to send for a corrugated printing quote
- Process: postprint, preprint, litho-lam or a mix; press type and maximum print area.
- For flexo: plate gauge, flute types, ink system and whether you mount on carrier sheets or sleeves.
- For litho-lam: offset plate size, gauge and platesetter type.
- Monthly plate area and number of new designs per month.
MOQ, price and lead time are confirmed in the quotation.
FAQ
How are corrugated boxes printed?
Mainly in three ways: postprint flexo directly on the combined board, preprint flexo on the liner reel before corrugating, and litho-lamination, where an offset-printed sheet is laminated onto the board. Inkjet printing is also used for some boxes.
What is the difference between preprint and postprint corrugated?
Postprint prints on finished, fluted board in a printer slotter or flexo folder gluer, using thick, soft plates. Preprint prints the flat liner reel on a wide-web flexo press before the corrugator, using thinner plates and giving better graphics, but it needs large repeat volumes.
What is litho-lamination in corrugated packaging?
Litho-lamination prints the graphic on paper by sheetfed offset with aluminium CTP plates, then laminates that sheet onto corrugated board. It gives offset image quality for display and premium boxes.
Which printing process is best for retail-ready corrugated boxes?
It depends on volume and graphics. Postprint with digital plates covers many retail-ready boxes; preprint suits large repeat volumes with high graphics; litho-lam suits premium display boxes where offset quality is required.
What plates are used for corrugated box printing?
Postprint uses thick, soft corrugated flexo plates; preprint uses thinner digital flexo plates; litho-lamination uses offset thermal CTP or CTcP plates. Our corrugated flexo plate page covers gauges and hardness in detail.
Reviewing how your box plant prints? Request a quote — tell us your print process, press type, plate gauge or size and monthly volume. Or request trial plates / contact us.
Disclaimer: values on this page are typical and for reference only; final specifications, MOQ, price and lead time are subject to the grade TDS and the quotation.
