What Actually Happens When a Barcode Won't Scan at 3 AM

I spent five years on the receiving dock at Amazon. Here's what I learned about barcodes that nobody tells you in the spec sheets.

## The Quiet Zone Is Not Optional

Every barcode standard—UPC, EAN, Code 128, ITF-14—requires blank space on both sides. The spec calls this the "quiet zone." At 3 AM

with a conveyor belt doing 40 cartons per minute, a barcode without enough quiet zone doesn't scan at all. The laser needs that