How to Select Ink for Pharmaceutical Blister Printing

Selecting the right ink for pharmaceutical blister printing is rarely a one-variable decision. The foil substrate, the print process, the intended message legibility, the drying conditions on the line, and the compatibility with any coating or lacquer already applied all contribute to whether a chosen ink will perform reliably in regular production.

At Axion Group we work with pharmaceutical manufacturers to supply specialist inks intended for blister-pack printing. Every recommendation is preceded by a review of the customer's actual application — because a product that prints cleanly on one aluminium foil grade may behave differently on another.

Substrate compatibility

Aluminium blister foils are supplied by numerous mills with different surface treatments, lacquers, and roughness profiles. An ink formulated for a hard-lacquered foil may exhibit poor adhesion on a softer surface, and vice versa. Before recommending an ink we typically ask for:

• Foil supplier and grade reference
• Existing lacquer / heat-seal coating on the print side
• Print orientation (print-then-form or form-then-print)
• Any secondary process the printed foil will pass through (deep-draw forming, sealing, autoclaving)

If the foil grade changes on a repeat order, the appropriate response is a small-scale trial rather than an assumption that the previous ink will continue to perform.

Print process and equipment

Rotogravure, flexographic, and pad-printing processes place different demands on the ink. Rotogravure inks are formulated for engraved cylinders and generally require different viscosity and drying characteristics than flexographic inks used on photopolymer plates. A press change — even a change of anilox roll — is a reasonable trigger to re-verify ink suitability rather than assuming the previous product will transfer directly.

Ink handling on the press matters too. Circulation temperature, viscosity control, and the cleanliness of press furniture all contribute to consistent print quality. Where a print defect appears, the ink is not always the cause; a systematic review of the press, the plate, and the substrate should accompany any ink-focused investigation.

Regulatory considerations

Pharmaceutical primary and secondary packaging is subject to the regulatory framework applicable in the market of use. We do not make regulatory approval claims on this website. Suitability for a given pharmaceutical application must be established by the customer through appropriate documentation and testing under actual production conditions. Where technical documentation is available for a specific product, it will be shared on request with qualified customers.

Application testing before regular supply

For any new ink recommendation, we suggest a structured trial sequence:

1. Bench trial — small-quantity print on the customer's substrate at the customer's plant, using representative press settings.
2. Short production run — after the bench trial is satisfactory, a limited production quantity is printed and evaluated for legibility, adhesion, and any post-process effects (heat sealing, forming).
3. Documentation review — the technical data available for the product is reviewed against the customer's internal specifications and change-control procedures.
4. Regular supply — regular orders are placed only once the trial has been formally reviewed and approved by the customer's quality function.

Skipping this sequence — for example, moving straight from a sample dispatch to a full production order — increases the risk of a batch problem that could have been anticipated in a shorter trial.

Working with your supplier

The relationship between a pharmaceutical manufacturer and its ink supplier should support the trial process, not compete with it. When you talk to Axion Group, expect to be asked about substrate, press, and application in detail before a product is recommended. A supplier that provides an ink recommendation without asking those questions is offering less than the process requires.

If you are considering a change of blister-printing ink — whether to consolidate suppliers, improve print performance, or evaluate alternatives — get in touch and we will walk through the trial process for your specific application. We will typically ask for foil supplier and grade, press platform, line speed, drying arrangement, and the downstream processes the printed foil will encounter, so that the shortlist we propose is genuinely relevant to your line.