Plans, resources, company information, and legal documents.
A companion to our bin-naming guide. The name is half the job. The print is the other half, and it's where most warehouses lose accuracy.
A few weeks ago we wrote about how to name your bin locations. It got more responses than anything else we have written, mostly along the lines of "the name is fine; what about the actual physical label?" That's fair. The label is where the naming hits reality, and it's where most warehouses we visit have at least one preventable problem.
This is a companion piece. It is about the physical print itself: how to make a barcode that scans reliably under warehouse conditions, what to put around it, and what to do when it stops working.
Leave a quiet zone
A quiet zone is the blank margin around the barcode itself. The scanner uses it as a reference for where the barcode starts and ends. Most barcode standards require a quiet zone of at least 10 times the width of the narrowest bar. Most labels we see in actual warehouses have a quiet zone of one or two times that. Sometimes none.
A barcode with too little quiet zone scans about 80% of the time in good conditions and 30% of the time when the scan angle is bad. A barcode with proper quiet zone scans 99% of the time in both. This is the single highest-leverage change you can make to label design.
We have had customers fix scan-failure rates of 12% by widening the white space around the barcode. The label looks emptier. It works much better.
Contrast matters more than resolution
A 600 DPI inkjet printer produces a sharper barcode than a 300 DPI thermal printer. The thermal printer's barcode will scan more reliably under warehouse conditions every time.
The reason is contrast. Thermal printing produces a dense, opaque black on white. Inkjet's black is slightly translucent and absorbs slightly into the paper, which lowers the contrast at the edges. Scanners care about the edge transition between black and white more than they care about resolution.
This is why thermal label printers dominate warehouse environments despite being lower-resolution and more limited in fonts. They produce labels that scan more reliably under poor lighting, scuffing, and partial occlusion. Use one.
Font selection for the human-readable text
Above (or below) the barcode you'll want the bin name printed in text large enough to read from across an aisle. Two opinions.
Use a monospaced font. Variable-width fonts like Arial or Helvetica look better in a marketing brochure and worse on a warehouse label. The fixed character width of a monospace font gives the eye a regular rhythm that's easier to parse from a distance. We use Roboto Mono or IBM Plex Mono. Both are free.
Don't use a serif font. Serifs disappear at distance. From three meters away in warehouse lighting, "B-A04-12" in Times New Roman is harder to read than the same text in a clean sans-serif or monospace. The serif is a typographic flourish that produces operational cost.
Size for the worst case
We size labels for a 3-meter scan distance and a 6-meter visual read distance. Concretely this means the text is at least 36 points (about half an inch tall) and the barcode is at least 1.5 inches wide for the Code 128 format we recommend.
Labels we see in the field are routinely too small, because they were designed at a desk by someone looking at them from a foot away. The designer felt good about the proportions. The picker squinting at the label from across the aisle does not.
Print one label, mount it where it will actually live, and walk away from it. Try to read the text from the position a picker would actually approach it. If you can't, make it bigger.
Mounting and adhesive
We mostly cover this in the bin-naming guide, but two refinements.
The adhesive matters more than the substrate. A vinyl label with cheap adhesive will peel off in a freezer within a month. A paper label with industrial adhesive can survive years if the paper is rated for the temperature. Ask your label supplier what their adhesive is rated for. If they don't know, switch suppliers.
Mount labels behind a clear acrylic shield in any environment with forklift traffic or pallet jack contact. The shield costs about $0.40 per location and prevents the most common cause of label loss (forklift forks catching the edge of a label and tearing it off). Pay the $0.40.
Re-print policy
Labels need to be inspected on a schedule. We recommend a quarterly walk of every aisle by someone whose explicit job is to identify damaged labels. Most warehouses don't do this and discover bad labels through scan failures, which is much more expensive.
A damaged label that's still scanning is on borrowed time. Replace it now, while you know what it says, rather than later, when the scan failure forces you to look up the bin name in three other places.
Test under your conditions
The most important thing in this post: nothing we wrote is a substitute for testing labels in your actual warehouse. Print a batch. Stick them up. Walk through scan workflows. Adjust. The right size, contrast, mounting, and font for your operation depend on factors we can't enumerate here (lighting, dust, freezer condensation, the eyesight of your specific team).
One afternoon of testing now saves a decade of accumulated scan failures. We watched a customer's accuracy rate jump three percentage points after they redesigned their labels following a half-day of in-warehouse testing. No software change. Just better labels.