Resources · Reference
Flexo printing glossary.
The language of flexography, in plain English — 22 key terms every label and packaging buyer runs into, defined clearly.
- Anilox roll
- A precision-engraved metering roll covered in tiny cells that carry a controlled, even film of ink to the printing plate. Its cell volume largely determines how much ink is laid down.
- Chill roll
- A cooled roller that draws heat out of the web straight after curing or drying, keeping thin, heat-sensitive films (such as shrink sleeve) flat and stable.
- Cold foil
- An inline process that applies metallic foil to the web using an adhesive and a printing station — a lower-cost, high-speed alternative to hot foil stamping for metallic effects.
- Corona treatment
- An electrical surface treatment that raises the surface energy of films so inks and adhesives bond properly. Essential for printing on many plastic substrates.
- Die-cutting
- Cutting the printed web to the final label or blank shape. Rotary die-cutting uses a cylindrical die inline at full speed; flat-bed die-cutting is slower but suits certain shapes and materials.
- Doctor blade
- A thin blade that wipes excess ink from the anilox roll so only the ink held in its cells transfers — giving consistent, controlled ink density.
- Flexography (flexo)
- A roll-fed printing process that uses flexible photopolymer relief plates and fast-drying inks to print on a wide range of substrates — labels, film, paper, foil and board. Alliance builds flexo presses.
- Impression cylinder
- The cylinder that backs the substrate and presses it against the plate cylinder so ink transfers cleanly and evenly.
- In-mould label (IML)
- A label placed inside the mould during plastic moulding so it fuses with the container wall, becoming part of the product rather than an applied sticker.
- Lamination
- Bonding a second film or layer onto the printed web — for durability, barrier or finish. Done inline (DeLam-ReLam) or offline.
- Makeready
- The setup work to get a new job running in register and to colour before good production starts. Makeready time and waste are among the biggest running costs, and are what servo drives reduce.
- Matrix
- The waste web (the skeleton) left after die-cutting labels, stripped away and rewound separately from the finished labels.
- Narrow / mid / wide web
- How presses are grouped by material width: narrow web (up to ~430 mm) for labels, mid web (~430–670 mm) for labels plus shrink sleeve and short-run packaging, and wide web (670 mm+) for higher-volume flexible packaging.
- Photopolymer plate
- The flexible relief printing plate used in flexo. A light-sensitive polymer is exposed and washed so the raised areas carry ink to the substrate — one plate per colour.
- Registration
- The precise alignment of each colour and process to the others. Tight, repeatable registration is critical for quality; servo presses hold and recall it automatically.
- Repeat length
- The circumference of one print around the cylinder — effectively the length of one label or design down the web. Servo (gearless) presses change repeat digitally; geared presses need gear/cylinder changes.
- Servo (gearless) drive
- A drive system where each print station has its own electronically synchronised servo motor instead of a shared gear train — enabling fast digital job changes, minimal setup waste and automatic registration.
- Shrink sleeve
- A printed heat-shrinkable film (PVC, PET-G or OPS) that wraps a container and shrinks to fit with heat. It demands thin-film handling, opaque white and chill drying.
- Substrate
- The material being printed — self-adhesive label stock, unsupported film, paper, foil, board or laminate. A multi-substrate press handles many of these on one line.
- UV / LED curing
- Instant curing of UV-reactive inks with ultraviolet (mercury) or LED-UV lamps. It cures on contact, allowing high speeds and printing on non-absorbent films.
- Unwind & rewind
- The reel of raw substrate feeding into the press (unwind) and the finished printed reel coming off it (rewind). Their maximum diameters set how long the press can run between reel changes.
- Web
- The continuous strip of material running through the press. Web width is the widest reel the press can print across — the single most important sizing spec.