Color
High contrast is critical to scan-ability. The scanner must be able to distinguish each bar reliably. It is best to use a black barcode on a white background. Never run the barcode across a background image or color change. Never "reverse" the barcode (e.g., white on black). Never use a red or reddish barcode, as scanners cannot read these colors.

Position
The scanner must be able to distinguish where the barcode begins and ends. It requires a "quiet zone" of space around the entire barcode of at least 0.117". The quiet zone should be the same color as the barcode background (preferably white) and contain no graphics, text or perforations. Position the barcode horizontally in the lower right hand corner of the coupon to avoid hard-to-handle issues.

Size
Never shrink barcodes smaller than 80% of full size to avoid scanner errors. Barcodes must always be sized proportionately (height and width together). For best results, all sizing should be handled during creation. Truncation (vertical shortening of the bars) is strongly discouraged, as it may reduce scan-ability.

Paper
Ideally, coupons should be printed on heavy white paper stock. Whatever the medium, the barcode should appear exceptionally crisp to the human eye. Glossy finishes should be avoided, as reflections may cause problems during scanning. Also avoid sticky coatings, as the material may distort or block the barcode.