Packaging print processes explained: flexo, offset, gravure, digital and what each does to your design

The five processes

Flexo: the workhorse

Flexo prints most of what sits on an Australian supermarket shelf that is not a folding carton: labels, pouches, flow wraps, bags and the corrugated it ships in. Modern flexo with HD plates and expanded gamut (CMYK plus orange, green and violet) prints photography well. Its limits are physical: the soft plate squashes slightly against the substrate, so dots and lines grow (dot gain), fine reversed type fills in, and solids can show a slight unevenness on absorbent board.

• Minimum positive type on film and coated label stock: about 4 to 5 point; reversed out of a solid: 6 to 8 point, sans serif, no hairlines.
• On corrugated (post-print flexo straight onto the liner): minimum 8 to 10 point, reversed type 12 point plus, line weights 0.5 mm or more, and avoid fine screens; expect visible board texture and washboarding across flutes.
• Spot colours are mixed and matched, so brand colours are reliable. Expanded-gamut presses can simulate most spots from seven inks and save plates on multi-version jobs.
• White ink is a separate station on clear and metallised film; it must be in the artwork as its own separation, and its opacity decides how clean the colours above it look.
• Registration tolerance is wider than offset; avoid designs that rely on tight trap between two colours (a thin keyline around a solid, type in one colour sitting on a solid of another).
• Plates are cheap to remake relative to gravure cylinders, so design changes are affordable; make-ready waste is the real cost on short runs.

Offset: cartons and fine detail

Sheet-fed offset is the process for folding cartons and for premium labels on paper. It holds the finest detail of any process: 4 point type, delicate serifs, smooth vignettes, photographic skin tones. The sheet goes through a coater for varnish or UV, then to a die-cutter, and then to the gluer. Most finishes (foil, emboss, spot UV, soft-touch) are offline passes after printing.

• Minimum type: 4 point positive, 5 to 6 point reversed; hairlines down to 0.1 mm hold on coated board.
• Solids are flat and even; heavy coverage benefits from a double hit or a dense ink and sealing varnish to avoid scuffing.
• Spot colours are standard; metallic inks and pearlescents print as spots, with the caveat that they look better on a sealed white board than on uncoated.
• Board choice drives everything: SBS (solid bleached) for the brightest white and sharpest print, FBB (folding box board) as the general carton board, uncoated or kraft for a natural look with lower contrast and more dot gain.
• Nesting on the sheet decides cost; the dieline guide covers why an odd carton size is expensive.

Gravure: consistency at scale

Gravure engraves the image into a chromed cylinder per colour. It delivers the deepest, most even solids and the most repeatable colour over very long runs, which is why national confectionery, snack and pet food bags use it. The cylinders are the cost: each one is engraved for one design, so a copy change means a new cylinder, and a seven-colour design is seven cylinders. Below 50,000 to 100,000 units gravure rarely makes sense; above that it is often the cheapest and best.

• Fine type can show a slightly ragged edge because the image is made of cells; keep text 5 point plus and avoid very fine serifs.
• Vignettes and skin tones are excellent; solids are its strength.
• Design for a long life. Build variants so that only one or two cylinders change between SKUs (common base art, one variant cylinder).
• Lead times are longer (cylinder engraving) and the minimum order is set by the converter.

Digital: flexibility and its limits

Digital presses (HP Indigo liquid toner, dry toner, UV and water-based inkjet) print from file with no plates. The unit cost does not fall with volume, which makes digital the right choice for short runs, many versions, test markets, seasonal packs and anything that changes often. It is also how most prototypes and pre-launch samples are made.

• Colour is CMYK, sometimes with orange, violet and green added; spot colours are simulated. Check the brand colour against the press's gamut before committing, and expect a visible difference from the flexo or offset version of the same pack.
• White and some metallics are available on some presses (Indigo white, inkjet white) and not others. Confirm before designing a clear label or a metallic effect.
• Type and detail are excellent; registration is perfect because there is one impression.
• Substrate ranges are narrower; some films and boards need pre-treatment or a primer, and not every laminate structure is available for digital pouches.
• Digital finishes (digital foil, digital spot UV) exist and avoid tooling, at a higher unit price than the offline equivalents.

Direct decoration: cans, glass, tubes

When the container itself is printed, the container maker's process rules. Aluminium cans are printed by dry offset on a mandrel: typically up to six or eight colours, printed wet-on-wet with a single blanket, so colours cannot overlap cleanly and trap is limited; design with butt-registered flat colours, keep type bold, and expect the can maker to supply a template with the no-print seam and the base. Glass and rigid plastics take screen printing (opaque, tactile, one colour per pass, bold shapes), or a pressure-sensitive or shrink-sleeve label when the design is complex. Laminate tubes print by flexo or offset flat before forming; extruded tubes by dry offset or screen after. Closures are pad printed or hot-foiled. Shrink sleeves are printed flexo or gravure on film, reverse-printed and shrunk to the container, and need artwork distorted to the sleeve's shrink profile, which the sleeve printer provides.

Choosing the process

Designing to the process

• Fix the process before the design. The colour palette, type sizes and effects follow from it.
• Ask the printer for their minimum type size, minimum line weight, minimum dot and registration tolerance in writing, and design above them.
• Build white and metallic as separations with their own layer and swatch, not as a visual effect.
• Get a drawdown or a printed sample of the brand colours on the real substrate before artwork; a colour that is right on screen and wrong on kraft is a reprint.
• Avoid tight trap between colours on flexo; use a common keyline or design the elements to butt rather than overprint.
• On flexo and gravure, plan range variants so that most plates or cylinders are shared.
• Proof on the process that will print, not a digital proof for a gravure job; ask for a press proof or a wet proof on long runs.

Written by

Morice Kastoun, Founder & Creative Director

Morice Kastoun is the founder and creative director of Morice&Co., an independent Melbourne branding and packaging studio. His packaging has shipped through the compliance processes of Coles, Woolworths, Chemist Warehouse, Priceline, Petbarn, Big W, Myer and Sephora US.