Coding technology comparison (CIJ vs TIJ vs TTO vs laser)

Putting a best-before date, a batch code or a barcode onto a product is one job with four main answers, and choosing the wrong one is an expensive mistake to live with on a production line. The four core coding technologies are continuous inkjet, thermal inkjet, thermal transfer overprinting and laser, and each is suited to particular materials, code types, line speeds and budgets. There is no single best technology, only the right one for what you are coding and onto what. This guide explains how each works, what it does well, where it struggles, and how to choose, so you can specify a coder properly or sense-check a quote rather than take a salesperson’s word for it.

What are you actually coding, and onto what?

Before comparing technologies, answer four questions about the job, because they decide the choice between them. First, the substrate: is it a plastic bottle, a film wrapper, a cardboard carton, a glass jar, a metal can or a printed label? Materials behave very differently under ink and under a laser. Second, the code itself: a simple date and lot code is undemanding, but a high-resolution barcode, a GS1 2D matrix or a block of variable data needs a technology that can render it cleanly. Third, the line speed and the throw distance: a slow hand-pack line and a high-speed bottling line have very different needs, and how far the printhead sits from the product matters. Fourth, the environment: washdown, dust, heat and the regulatory demands of food or pharmaceutical production all narrow the field. Hold those four answers in mind as you read, because every technology below is strong on some and weak on others.

How does continuous inkjet (CIJ) work, and when is it the right choice?

Continuous inkjet is the workhorse of date and batch coding, and it is the right choice when you need to code almost any material at speed without touching the product. A CIJ printer forces ink under high pressure through a nozzle to create a continuous stream of tiny droplets, charges the droplets it needs and deflects them onto the product while the rest are recirculated. Because it is non-contact and fires from a short distance, it codes happily onto curved, uneven and moving surfaces, which is why you see it on bottles, cans, cables, pipes and flexible packs. It handles a very wide range of substrates, plastic, metal, glass, paper, cardboard and more, at high line speeds, and it suits the small character date, time and lot codes that most food, beverage and general manufacturing lines need.

The trade-offs are resolution and consumables. CIJ is built for small, fast codes rather than crisp high-resolution barcodes or graphics, so if your priority is a perfect 2D matrix it is not the natural pick. It also runs on ink and make-up solvent, which are ongoing consumables, and the printhead needs periodic maintenance, though modern units have reduced both. Domino’s Ax-Series covers this ground from the essential Ax130i up to the high-uptime Ax550i, with the G50i as a simpler entry unit, and they offer specialist inks for food contact, condensation, high-grip and other conditions.

How does thermal inkjet (TIJ) work, and when is it the right choice?

Thermal inkjet is the right choice when print quality matters, especially for barcodes, 2D codes and crisp text on flat or near-flat surfaces. A TIJ printhead heats tiny chambers of ink so that each forms a bubble that ejects a precise droplet, and because the droplets are small and controlled the result is razor-sharp. TIJ produces high-resolution characters, logos and machine-readable codes, and it does so from a cartridge that clicks in and out, so there is very little maintenance and no separate solvent system to manage. It is fast enough for most lines, printing hundreds to over a thousand characters a second, and the clean output makes it the go-to for GS1 barcodes and the 2D data-matrix codes that retail and pharmaceutical traceability increasingly demand.

Its limits are throw distance and substrate. TIJ wants to be close to the surface and works best on porous materials such as cartons and paper, although solvent-based and specialist inks now extend it to many non-porous films and plastics. It is less suited to very uneven or distant surfaces where CIJ shines, and on very high volumes the cartridge cost per code is worth checking against alternatives. Domino’s Gx-Series covers this need, from the single-head Gx150i to the multi-head Gx350i, with a high-resolution Gx-Series PRO printhead for the best print quality.

How does thermal transfer overprinting (TTO) work, and when is it the right choice?

Thermal transfer overprinting is the right choice for coding directly onto flexible films and labels, the kind of packaging used for snacks, fresh food, pouches and flow-wrapped products. A TTO printer uses a thermal printhead pressed against a ribbon, melting ink from the ribbon onto the film as it passes, which gives a clean, high-resolution print of dates, batch data, barcodes and even real-time variable information. Because it prints onto the film before or as the pack is formed, it suits horizontal and vertical form-fill-seal lines and labelling applications, and the quality is high enough for barcodes and detailed text.

The main consumable is the ribbon, and the technology is specific to flexible film and label substrates rather than rigid containers or cases, so it is a focused tool rather than a general-purpose one. Where your packaging is film, though, it is usually the cleanest and most capable option, and Domino’s Vx-Series is built for exactly this, with efficient ribbon use to keep the running cost down.

How does laser coding work, and what is the difference between CO2 and fibre?

Laser coding is the right choice when you want a permanent, consumable-free mark at high speed, and the choice between CO2 and fibre comes down entirely to the material. A laser coder marks by directing focused light at the surface, where the energy causes a colour change, an etch or an ablation of a coating, leaving a permanent code with no ink, no solvent and no ribbon. Lasers are fast, capable of very high character rates, and once installed they have low running costs and long service lives, which is why they suit high-volume lines and any application where a code must not rub off.

The material decides the laser type. A CO2 laser, with its longer wavelength, is suited to organic and non-metal materials: paper, cardboard, glass, coated plastics, PVC and many food and beverage packs, and it is the common choice for coding cartons and bottles. A fibre laser, with a much shorter wavelength and a far finer, more intense focus, is the choice for metals and hard plastics, producing high-contrast permanent serial numbers, barcodes and data-matrix codes on cans, tools and components. Fibre units also run at lower power and are effectively maintenance-free with very long lifetimes, while CO2 systems cost less to buy but use more energy. One practical point with any laser is fume: marking releases particulate and vapour that must be captured, so a laser installation usually needs an extraction and filtration unit alongside it. Domino’s Dx-Series covers CO2 from the Dx260i up to the higher-power Dx660i, the F-Series covers fibre for metals and hard plastics, and the DPX fume extraction units handle the extraction side.

What about coding outer cases and pallets?

Coding the outer case or the pallet is a separate job from coding the primary pack, and it has its own tools. For printing large characters, logos and barcodes directly onto a shipping case, a direct case coder applies a high-resolution print straight onto the corrugated board, which removes the cost and waste of pre-printed boxes or stuck-on labels. Where a printed-and-applied label is required, for GS1 logistics labels on cases and pallets for example, a print-and-apply system prints the label and places it automatically on the line. Domino’s Cx-Series handles direct case coding and the Mx-Series handles print and apply, and our direct case coding guide works through the cost case for switching away from pre-printed boxes.

How do running costs and maintenance compare?

The purchase price is only part of the cost, and the technologies differ as much in what they cost to run as in what they cost to buy. Continuous inkjet runs on ink and make-up solvent and needs periodic printhead servicing, so it has a steady consumable cost but a modest purchase price. Thermal inkjet uses cartridges that combine ink and printhead, which keeps maintenance very low but means the cost lives in the cartridge, worth modelling on very high volumes. Thermal transfer uses a ribbon, and ribbon-saving features matter to the running cost. Laser has the highest purchase price and needs fume extraction, but it has effectively no marking consumable and a long, low-maintenance life, so it tends to win on total cost where volumes are high and the line runs for years. The right comparison is not the sticker price but the cost per code over the life of the line, including consumables, maintenance, downtime and waste, and we will work that through with you for your own volumes.