Printing Types and Where CI Flexo Fits

The same shelf in the same store carries packaging printed four different ways, and the customer cannot tell which is which. The converter can, because the printing type decides the job it can take: run length, substrate, colour depth, number of SKUs, and how the printed film will behave in the lamination that follows. Choosing a printing method is not a question of which one is better - each of the four mainstream types does something the others cannot - but of which one matches the order book. This guide sets the four side by side, narrows to the three structures of flexo, and places the CI flexo printing machine where it belongs in that map.

THE FOUR PRINCIPLES

The four printing types differ in how the image meets the substrate, and that difference sets everything else. Flexographic printing uses a raised image on a photopolymer plate or sleeve, transfers ink from an anilox roller, and prints from roll to roll at production speeds: the workhorse of flexible packaging, comfortable on film, foil and paper alike. Rotogravure engraves the image into a cylinder, carries a heavy, even ink film, and delivers the finest tonal depth of the four - the choice for very long runs where the cylinder engraving is paid back by the volume and the brand cannot accept a compromise in colour. Offset printing transfers the image from a plate via a blanket, dominates carton and label work on paper and board, and is rarely the tool for unsupported film. Digital printing removes the plate entirely: no make-ready, no minimum run worth mentioning, variable data per copy - the natural home of short runs, prototypes and personalised campaigns, with a per-copy burden that rises as the run grows. Every printing choice is a bet on where a job will sit among those four: long or short, film or board, deep colour or fast changeover. The four types are not rivals on a catalogue page - they are different answers to different order books, and a plant that runs two of them is not hedging but matching its equipment to the work it actually sells.

THE FLEXO SPLIT: STACK, INLINE AND CI

Flexo itself comes in three structures, and the difference matters most on film. A stack press arranges its colour stations vertically, which keeps the machine compact and the web path short. An inline press arranges its stations in a line, giving the operator easy access and room for downstream units - coating, lamination, die-cutting - in one pass. A CI press - common impression - mounts every colour station around one large central drum, so the web is held on that single impression cylinder while all colours print. The consequence is stability: the web does not change length between stations, registration stays tight at speed, and a thin, extensible film behaves far better than it would in a machine where each station's tension acts independently. That is why the flexible film world - the world of thin PE, PET and BOPP structures - keeps returning to the CI architecture for anything that has to hold register at production speed. The CI architecture has its own trade-offs, honestly stated: the central drum fixes the machine's effective width, so a CI press is bought for a width band and stays there; and the plate or sleeve changes happen around a single impression, so the changeover discipline matters more than on a stack press. Neither is a flaw - they are the conditions of the stability the architecture buys.

WHERE CI FLEXO SITS IN THE FILM WORLD

The CI flexo printing machine supplied through this line sits in the middle of the film map, and its specification tells the story: eco inks in both water-based and solvent-based chemistry, photosensitive resin plates, a maximum feeding width of 800 mm, printing widths from 100 to 600 mm and speeds reaching 150 m/min. That combination - moderate speed, moderate width, wide ink compatibility - is the productive middle ground of flexible packaging. Above it sits gravure, superior for very long runs and the deepest colour work, but slower to change over and less forgiving of short campaigns. Below it sits digital, luxurious for short runs and customisation, but with an economic curve that turns steep as volume grows. The CI flexo occupies the volume band where most flexible packaging actually lives: medium and long runs, repeat orders, several SKUs on one machine, and a brand that needs the same result next quarter.

THE INK AND LAMINATION HANDOFF

Printing types are usually compared on the press, but in flexible packaging the comparison continues after it. The printed film goes into the solventless laminating machine, and the ink system decides how that handoff behaves: water-based inks need their drying managed before the film is laminated, solvent-based inks need their residual solvents managed, and both need to be compatible with the adhesive that will bond the next web. This is where flexo's ink flexibility pays for itself - the same press can run a water-based job for one structure and a solvent-based job for another, and the lamination stage is specified against what the press actually produced. A printing type chosen without the lamination stage in view is only half a decision. Print position matters too: surface printing keeps the ink outside the laminate, where it is exposed to the product and the customer's handling, while reverse printing traps the decoration between webs, protected by the laminate - and each position sets its own requirements on the ink, the adhesive and the bond between them.

CHOOSING AMONG THE TYPES

The practical map is drawn with four questions. How long is the run - does the job justify a cylinder, a plate set, or nothing at all? What is the substrate - film goes to flexo or gravure, board to offset, short and changeable to digital? How deep must the colour go - a brand-critical gradient or photographic image may pull towards gravure, while solid areas, line work and text sit comfortably in flexo? And how many SKUs will the machine carry - a press that changes over quickly earns its keep on a catalogue of medium runs. A converter who answers those four honestly usually finds the printing type chooses itself - and finds flexo, and within flexo the CI structure, holding the largest share of the answer. The expensive mistakes are the mismatches: a gravure-class image pushed onto a press that cannot hold its depth, a short-run catalogue forced onto cylinders that will never be paid back, a board job sent to a film machine. Each one looks like a printing problem and is really an order-book problem - which is why the four questions come before the machine specification, not after it.

WHAT XIAOPAI SUPPLIES

XIAOPAI works with long-established Chinese manufacturers to supply the CI flexo printing machine class - water-based and solvent-based eco inks, photosensitive resin plates, up to 150 m/min, 800 mm maximum feeding width and 100 to 600 mm printing widths - alongside the laminating and slitting stages that follow it, as one specification conversation. The printing industry keeps widening the choice - digital printing keeps advancing and print performance technology keeps improving - and the CI flexo stays where it has always been: the productive centre of the flexible film world.