Coding and Marking: Thermal Inkjet Printers and Industrial Coders

A label tells a customer what the product is. A code tells you, and a regulator, and a recall investigator, exactly which batch it came from and when. They are different jobs, and quite often you need both.

Coding and marking is the printing that goes directly onto the pack: the date, the lot, the batch, the shift, the plant, the best before, the expiry, the case count. No label, no liner, no waste web. Just the mark, applied in line by a thermal inkjet printer or another coder, at the speed the line already runs at.

Marapack Services is the Pacific Northwest distributor for Altech labeling systems, and on the coding side we supply, install and support coding and marking equipment and supply the ink on standing orders. We lead with thermal inkjet, under our own specification and our own Marapack part numbers on the ink. In June 2026 alone we shipped 144 ink cartridges and a printer to five customers.

Not sure whether your line needs a code, a label or both? Book an equipment audit and we look at the pack, the substrate and the line before anything is specified.

What is a thermal inkjet printer?

A thermal inkjet printer, or TIJ printer, codes dates, lot numbers and barcodes directly onto packs from a sealed cartridge that holds both the ink and the printhead. Heating elements fire tiny ink drops at close range. When the cartridge is empty you replace it, and the printhead is new with it.

That design is the whole appeal. There is no printhead to clean, no make up solvent, no service kit, and no scheduled printhead replacement. The running cost is one consumable, so it is predictable.

It is a different machine from a thermal printer, which prints labels with heat on special stock, and from a desktop inkjet, which prints on paper. An industrial thermal inkjet printer is mounted on the line, triggered by a product sensor, and prints on the pack as it passes.

Should you code the pack or print and apply a label?

Code the pack directly when the only variable data is a date, lot, batch or shift and the surface is printable and clean. Print and apply a label when the data includes a barcode that must scan to a stated grade, when the surface will not take a good mark, or when a customer specification requires a label.

Settle this before choosing a printer.

Code it directly when:

• The only variable information is a date, lot, batch or shift
• The pack surface is printable and stays clean
• You already have a preprinted label or preprinted packaging carrying everything else
• You want the lowest cost per unit marked

Print and apply a label when:

• The variable data includes a barcode that has to be scanned and graded, such as a GS1-128 case label or a pallet SSCC
• The pack surface will not take a good mark: dusty, wet, waxed, deeply textured, or refrigerated
• The information is long enough that it needs the real estate of a label
• A customer specification requires a label

The label route is covered on our variable-data print and apply hub. Where the line is not a heavy duty one, the ALcode LT print and apply head is the economical version.

Many food and produce plants end up with both: a coder on the retail pack, a print and apply head on the case, a pallet labeler at the end of line. That is a normal shape, not a sign that something was specified badly.

Which coding and marking technologies do we supply?

We sell thermal inkjet printers under our own label, and we can supply thermal transfer overprinters and hot foil coders through the Altech distributor price list. We do not sell continuous inkjet or laser marking, and we say so rather than pretend. Each technology suits a different substrate and speed.

Being honest about this is more useful than a comparison chart, so here is the whole landscape with our position in it stated plainly.

Thermal inkjet, TIJ. We sell this.

A sealed cartridge holds both the ink and the printhead. When the ink runs out, you change the cartridge and you have a new printhead with it.

Why it suits food and produce coding: near zero maintenance, high resolution, quiet operation, and a running cost that is predictable because it is one consumable. The trade off is throw distance. TIJ prints at close range, typically a few millimeters from the substrate, so the pack has to be presented consistently.

This is the technology we lead with and the one we private label.

Thermal transfer overprinting, TTO. We can supply this.

A thermal printhead prints through a ribbon directly onto flexible film, inside the packaging machine. Very high resolution, no ink system at all, and the mark is on the film rather than on a label.

The Altech price list carries thermal transfer intermittent coders based on the Markem SmartDate X30 and X45, and we can supply them through the same distributor channel as the labeling and packaging equipment they integrate with. Right for flow wrapped, thermoformed and sealed film packs. Not applicable to a corrugated case.

Hot foil coding. We can supply this.

Hot foil printing units, in a compact 15 by 30 mm format (about 0.6 by 1.2 in) and a high performance version, plus an assembly for integrating a non Altech hot foil unit into an Altech machine. A simple, robust way to date code onto film and card where the volume of information is small.

Continuous inkjet, CIJ. We do not sell this.

CIJ is the incumbent technology in a lot of older plants: a charged ink stream, a long throw distance, high speed, and a real maintenance burden with make up solvent, filters and scheduled service.

We do not sell CIJ, and we would rather say so than pretend. Where a plant is running CIJ today, the question worth asking is whether the application still needs the throw distance and the speed, because if it does not, TIJ removes an entire maintenance category. Where it does, we will tell you that too. The mechanics are laid out side by side in our thermal inkjet vs continuous inkjet comparison.

Laser marking. We do not sell this.

Permanent, with no ink or ribbon to buy, and the right answer for some substrates. Not part of our range.

Which thermal inkjet printers are in the Marapack range?

The Marapack thermal inkjet range covers three printhead platforms under our own label: the Titan family on half inch printheads, the SJ Freedom family on one inch printheads, and SJ Infinity on a third platform. Handheld, single head and stitched multi head configurations reach up to 4 inches of print height.

The printhead platforms

TIJ cartridges come in a few printhead widths, and the width sets what you can print in one pass.

• Half inch printheads. The workhorse. One or two lines of text plus a small code, at the height typical date and lot coding needs. The lowest cost per cartridge and the widest ink range.
• One inch printheads. Twice the print height in one pass, for larger characters or more lines.
• Stitched multi head configurations. Two, four or more printheads aligned to print as one taller image, up to 4 inches of print height on the widest configuration.

The printers

These are available under our own label, with our own boot screen and our own part numbers on the ink.

Titan family, built on half inch printheads:

• Titan T6 handheld and Titan T9 handheld, portable units for marking cases, bags, boards, pipe and product away from a fixed line
• Titan single half inch printhead, the fixed mount workhorse and the configuration we standardize on
• Titan 21, one stitched 1 inch printhead
• Titan 22, two half inch printheads
• Titan 41, one stitched 2 inch printhead
• Titan 44, four half inch printheads

SJ Freedom family, built on one inch printheads:

• SJ Freedom Automatic and SJ Freedom Handheld
• SJ Freedom 21, one stitched 2 inch printhead
• SJ Freedom 22, two 1 inch printheads
• SJ Freedom 41, one stitched 4 inch printhead
• SJ Freedom 42, two stitched 2 inch printheads
• SJ Freedom 44, four 1 inch printheads

SJ Infinity, on a third printhead platform, for applications where that platform's cartridge chemistry or cost profile is the better fit.

Which ink does your substrate need?

Your substrate decides the ink. Porous surfaces such as uncoated corrugate, kraft and paper absorb ink, so water based ink is right and cheapest. Non porous surfaces such as coated cartons, plastics, films and foils need solvent based ink, because a water based ink on them will smear indefinitely.

Choosing the printer is easy. Choosing the ink is where coding projects succeed or fail.

Porous means the substrate absorbs ink. Uncoated corrugated cases, kraft paper, uncoated cartons, paper bags. Water based ink is right, it is the lowest cost per code, and it dries by absorption.

Non porous means the ink has to dry on the surface. Coated cartons, plastics, films, foils, shrink wrap, laminated stock, glossy label faces. Solvent based ink is required.

Our ink range, under Marapack part numbers:

What gets coded, and where

Case and carton coding

A core application in food and produce plants. Date, lot, batch, plant code and shift, printed onto the case as it passes on the conveyor.

The choice is between a TIJ head mounted over the case line and, where the case also needs a scannable barcode, a print and apply label. TIJ is usually the cheaper option per case. A label is required when the data has to be graded as a barcode, which is the situation on produce cases under the Produce Traceability Initiative; the equipment for that is on our PTI labeling systems page.

Date, lot and expiry coding on retail packs

Best before, use by, packed on, lot. On film, on card, on a preprinted label, on the pack itself. Substrate decides the ink, and pack presentation decides the mounting.

Coding onto an applied label

A common and underused arrangement: preprint everything fixed on the label, apply it with a labeling head, and code the variable part onto the applied label in line. Cheaper than print and apply, and it keeps the label converter's print quality on the fixed content.

Handheld and off line marking

Marking product, cases, bags, boards, pipe or stock away from a fixed line. The handheld units in the Titan and SJ Freedom families cover this, and they are the right answer for low volume, mixed product, warehouse marking and field work.

Coding inside a labeling machine

Where the coder needs to be part of the labeling system rather than a separate station, the Altech range carries integration assemblies for coders and hot foil units, plus the thermal transfer intermittent coders based on the Markem SmartDate X30 and X45. That means one machine, one control point and one supplier for the whole station. The labeling side of that station is covered on our labeling machines and lines hub.

What decides whether a coding install works?

Six things decide whether a coding install works, in the order they cause problems: the substrate, throw distance and pack presentation, line speed against print height, where the print trigger comes from, where the data comes from, and the environment. When a code smears or fades, check the first two before anything else.

1. Substrate. Porous or non porous, and how clean and dry it is at the moment of printing. Everything else follows.

2. Throw distance and pack presentation. TIJ prints at close range. If the pack wanders, the code fades on one side. A guide rail is cheaper than a technology change.

3. Line speed against print height. A taller print image at high speed needs more printhead width, which is why the multi head configurations exist.

4. Where the trigger comes from. The printer has to know a pack arrived, at the right moment, every time. A poorly placed product sensor causes faults that read exactly like printer faults.

5. The data. A fixed date typed in at shift start is a different system from a date pulled from your ERP or your line controller. Which one you need is a process decision before it is an equipment one.

6. Environment. Cold, wet, dusty. A chilled pack pulled into a warm room grows condensation in seconds and no ink dries on water.

What are the downsides of a thermal inkjet printer?

A thermal inkjet printer prints only at close range, so packs must be presented consistently; it needs solvent ink on non porous surfaces; and its cartridge is the running cost, so volume drives spend. Where a line needs a long throw distance or very high speed, continuous inkjet can be the better technology.

None of those is a reason to avoid TIJ; they are the reasons to specify it properly. A guide rail fixes presentation. The substrate test fixes the ink choice. A standing cartridge order fixes supply.

Print quality is the other limit worth knowing. If the mark carries a barcode, the fact that your handheld scanner reads it is not evidence that your customer's fixed scanner will. Print quality is a measured property with a defined grade, and a symbol can fail for reasons invisible to the eye. Where a customer requires a barcode to meet a stated grade, a printed label is usually the safer answer.

How do you keep coding ink supplied through the season?

Order ahead of the season, not during it. We supply the ink under our own part numbers and set up standing pre-season orders, because private-label ink is made to order rather than pulled off a shelf. A standing order means the cartridges for your peak weeks are ordered before those weeks start.

A coder is a machine you buy once and an ink account you keep forever. What matters:

• Availability. Running out of ink stops the line as surely as a failed printer, and produce plants run coding hardest in exactly the weeks when nothing can wait.
• Lead time. Private label ink carries a minimum processing time, so a same day order is not a plan. Standing orders ahead of season are.
• Chemistry consistency. Changing ink chemistry mid season changes dry time and adhesion, which changes results. Specify once, then hold it.
• Shelf life and storage. Cartridges have a shelf life and they do not like heat.

We would rather build the order with you in spring than take the phone call in July.

Frequently asked questions

What is the difference between TIJ and CIJ? Thermal inkjet keeps the printhead in the cartridge, so there is no printhead maintenance, no make up solvent and no service kit. Continuous inkjet has a permanent printhead, a longer throw distance and higher speed, and it carries an ongoing maintenance and consumable burden. We supply TIJ. Where CIJ is genuinely the right technology for the application, we will say so.

Can a thermal inkjet printer code onto plastic and film? Yes, with a solvent based ink. Water based ink on a non porous surface will not dry, and that mismatch is a common cause of a coding installation that smears.

Will it print a barcode? Yes. Whether the printed symbol holds up depends on substrate, print height, speed and ink, and it should be tested on your actual pack before you rely on it. Where your customer requires a barcode to meet a stated print quality grade, a printed label is usually the safer answer.

How much maintenance does a TIJ printer need? Very little, which is the point of the technology. There is no printhead to clean and no solvent system, because the printhead is part of the cartridge. What it does need is a clean, correctly presented pack and a stable trigger.

Can we code onto a case and a retail pack from one printer? Not usually from one head, because the substrates, print heights and mounting positions differ. Two heads on one line is normal, and the ink can often be the same if both substrates are in the same porosity class.

Do you supply the ink, or do we buy it elsewhere? We supply it, under our own part numbers. Because private-label ink is made to order, we set up a standing pre-season order with you so the cartridges are ordered ahead of the weeks your line cannot wait.

Should we test the ink on our pack before buying? Yes. Print on your actual pack, at your actual line speed and room temperature, and look at the code an hour later to see whether it smeared or faded. We will tell you what to test and what to look for, and we will tell you when the answer is a label rather than a code, or a guide rail rather than a printer.

Can you service coding equipment we already have? We support the printers we supply. For other coding equipment, bring us what is on the line and we will tell you honestly whether it should be retrofitted or replaced. On the labeling side of the same line, our labeling machine repair and service covers Altech, Label-Aire, PackLeader, CTM and Tach-It machines.

Get the substrate right before you buy a coder

The hour that settles a coding project is the one where a code is printed on your actual pack, at your actual line speed, in your actual room temperature, and somebody looks at the result an hour later to see whether it smeared. We walk the line, look at the pack and the substrate, and tell you which printer, which ink and which mounting, including when the answer is a label rather than a code. Call 253-709-5566 or request a coding line assessment.