First define whether the mark is a production date, best-before date, use-by date or another controlled field. Record the exact format, separator, language, time zone, offset rule and who is authorised to change it. A technically perfect print can still create a serious production problem if the wrong date logic is active.
Then define where the code sits and what it must survive. A date on a paper carton, coated label, plastic bottle or flexible film may need a different ink or ribbon. Check colour contrast, curvature, moisture, oil, condensation, heat, rub and whether a downstream label, seal or guide will cover the mark.
Choose the technology around movement at the print point. Hot foil is a low-cost route for short messages during an intermittent cycle. Thermal inkjet gives software-driven variable data on a sample-approved surface. TTO is normally the stronger comparison for high-quality date coding on flexible film in VFFS, flow-wrap and pouch machinery.
Build date verification into the operating procedure. At start-up and after every changeover, compare the displayed job and a first-off printed sample with the production order. Where the risk requires it, add scanner or vision verification and define whether a failure stops the line, rejects the pack or creates a controlled hold.
A useful trial uses the full date layout at normal and maximum line speed on production material. Record the printer settings, ink or ribbon, code position, drying or cooling time and any rub or handling test. Keep that record with the approved job so future service or consumable changes can be checked against the original result.
