During the transition to 2D barcodes, most retail packs carry two symbols: the linear barcode every till reads today, and the QR that phones, regulators and Sunrise-ready checkouts read. GS1's dual marking guidance keeps the two within 50 mm of each other, and that single number drives most of the layout decisions on small packaging.
Why proximity is a rule at all
A checkout operator makes one gesture per item. If the two symbols sit far apart, the scanner may capture the wrong one, capture both ambiguously, or force a second gesture, all of which costs seconds that multiply across a lane's day. Keeping related symbols within 50 mm means whichever code the optics find first, it is the right item, and the till can prefer whichever symbology it is configured for.
The arithmetic that decides your label
An EAN-13 at 100 percent magnification is 37.29 mm wide with its quiet zones. A typical Digital Link QR at retail module sizes prints at 16 to 20 mm per the size rules. Side by side with breathing room, you need roughly 55 to 60 mm of usable width, which many labels do not have: the worked example on our generator page is a 45 mm lip balm label, where side-by-side placement simply fails. The generator takes your label width and returns the verdict, with combined-width numbers, before design time is spent.
The layouts that work when width runs out
Stack vertically. The 50 mm applies center to center in any direction; a QR above the linear code is fully compliant and often the cleanest solution on tall narrow labels.
Shrink within limits. The QR's X-dimension can come down to the permitted floor before readability at the till is at risk; the linear code's magnification also has a permitted range. Shrink deliberately, never by letting a designer eyeball it.
Use an adjacent panel. On cartons, symbols on the same face near a shared edge can respect the spirit and the measurement; wrap-around placements on tight curves are where artwork checks earn their keep.
The one check that outranks layout
Both symbols must agree on the GTIN. Layout mistakes cost aesthetics; an identity mismatch costs a production run. Onpack's artwork verification compares the linear digits against the GTIN inside the 2D code before plates are made, which is the cheap insurance the pre-press checklist is built around.
Common questions
Where does the 50 mm figure come from?
GS1 dual marking guidance: when a pack carries both a linear barcode and a 2D code with related data, they should sit within 50 mm of each other so one scanning gesture captures either.
Do both codes have to carry the same GTIN?
Yes, and the pre-press check matters: a mismatch between the linear code's digits and the GTIN inside the QR is the most expensive artwork error, caught free by verification tooling.
What if my label is too narrow for both?
Stack them vertically, reduce the QR's X-dimension within the permitted range, or move one symbol to an adjacent panel. The generator's fit check does the arithmetic for your width.
Can I drop the linear barcode early?
Not for retail: tills that cannot yet read 2D codes still need the stripes. Dual marking is the transition state until 2D reading is universal.