Where to put labels and what material to use so they last

A freshly applied label scans almost every time. The real test comes three or five months later: the warehouse heats up in summer, labels on shelf edges start to curl, labels on the sides of cartons get scuffed by pallet trucks, and the print fades to pale grey. On count day the scanner stays silent in front of those labels, the operator falls back on typing, the pace drops and errors creep in. Labels that last and scan fast depend on three things: where they go, what they are made of and how they are looked after.

Where to put them

There is one rule for placement: easy for a hand and a scanner to reach, and always in the same place.

• Shelving: on the front face of the beam, between knee and shoulder height. Too low means crouching, too high means stretching, and a few extra seconds per bin adds up to hours over a thousand bins.
• Cartons: on the most visible side, and in the same corner for the whole batch, for example the lower left of the short side. Not over the sealing tape, and not across a fold or an edge, where the barcode distorts.
• Pallets: one label on each of two adjacent sides, at a height both a truck driver and a person on foot can see. If the pallet is stretch-wrapped, put the label outside the film or leave a window.
• Bins: facing the aisle and not hidden by goods. One label per bin, and never two different codes in the same spot.

The surface must be flat, dry and clean. Dust and grease are the main reason labels fall off, and a wipe with a dry cloth does more than pressing harder. Rough cardboard needs a stronger adhesive, and a cold store or a damp basement needs an adhesive made for low temperatures and moisture.

Material: pick what survives a summer

The two printing methods most often used in warehouses age very differently:

• Direct thermal labels need no ribbon and are cheap, but they dislike heat, light and rubbing, and the print fades over time. They suit short-lived carton labels.
• Thermal transfer labels use a ribbon to put the print on the label, so it resists wear and sunlight. On a synthetic label stock they can serve on a shelf for years, which suits bin, rack and pallet labels.

A few more details:

• Prefer a matt surface. Glossy lamination reflects the lights and the scanner fails to read.
• Black on white, with as much contrast as possible, and a blank margin all around the barcode.
• Size the barcode so it scans from an arm's length. A tiny print saves paper but slows every single scan.
• For shelves whose labels change often, use a clear pocket holder so you can swap the paper without sticking anything new.

A simple piece of arithmetic

Suppose a warehouse has 600 bin labels, all printed on direct thermal paper, and after the summer 90 have faded beyond reading. Finding them, reprinting and sticking them back takes about 3 minutes each, which is 270 minutes, or 4.5 hours, without counting the time lost during the count itself. Thermal transfer stock costs more than thermal paper, but 4.5 hours of labour and a delayed count usually cost more than the price difference. Work it out with your own prices; the point is to include the replacement labour in the cost.

Everyday upkeep

Labels are consumables, and someone has to look after them, or you only find out when they fail:

1. Walk the site once a month, scan a handful of bin labels and note the ones that fail.
2. A reprinted label keeps the original code, and the old one is removed. Never stick a new label over an old one, or one spot carries two codes.
3. Record the date and reason for each reprint. If one area keeps needing them, the position or the material is wrong.
4. Keep a small roll of blank labels and a marker in the warehouse so gaps can be filled on count day.

In short

A fixed position, a material meant for long service and a monthly walk-round keep labels scanning half a year on. InventoryHub numbers and prints labels for products, shelves and bins that have none, and the label position and material can be agreed before the visit, so later receiving can carry on with the same codes.