The date code

Marking the unit

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Inkjet coder Hand stamp Printed lot sticker Written on a cleared panel All four need the artwork to cooperate Where to put it Keep a marked unit from each run Decide the method before the artwork is drawn Build the check into packing, not into inspection References

This is the step that turns a compliance rule into a line decision.

Inkjet coder

A small printer on the line marking each unit as it passes. It is the standard industrial answer, it is fast, and it is capital a first production run usually does not have.

Hand stamp

A date stamp and an ink pad, applied to a cleared panel. It costs almost nothing, it is slow, and it is entirely workable at the scale most people start at.

Printed lot sticker

A small label printed per batch and applied by hand. Neat, reliable, and it adds a component and a step to every unit.

Written on a cleared panel

A space in the artwork with a pen line. Honest, legible if done carefully and messy if not, and it reads as handmade, which for some brands is the point.

All four need the artwork to cooperate

A clear area, flat enough, positioned where the chosen method can reach it. Designing the label without that space is what forces an ugly retrofit.

Where to put it

The base or the lower back panel, away from the front. It has to be clearly displayed rather than prominent, so somewhere a buyer can find it without it competing with the brand.

Keep a marked unit from each run

A retained sample with its own code on it, filed with the batch record. That is what makes a code useful later rather than merely compliant now.

Decide the method before the artwork is drawn

Each of the four needs a different amount of clear space in a different place. Choosing the method afterwards means either an ugly sticker across the design or a reprint.

Build the check into packing, not into inspection

The person applying the mark is the person best placed to notice it is missing. A separate inspection step later catches it after a pallet is already wrapped.

References

40 CFR 59.205, Labeling: "The container or package of each consumer product that is subject to this subpart shall clearly display the day, month, and year on which the product was manufactured, or a code indicating such date." Products distributed to consumers at no charge for sampling purposes are excluded. law.cornell.edu

The Davis Pack Supply catalog, measured 18 October 2026. The air and fabric shelf is 652 rows: 413 containers and 239 closures, from one archetype across five leaves. 356 PET and 57 glass, from 30 to 946 mL with a median of 200. The closures include 34 fine mist sprayers and 19 trigger sprayers, and 24-410 carries 192 of the containers.

Written from 40 CFR 59.203 and 59.205, and from the catalog as it stood on 18 October 2026. The VOC limits quoted for air fresheners come from search results rather than from Table 1 itself, which would not serve to us, and every page that uses them says so. Confirm them against the current table before setting a formula.