Protecting printed items intended for public exchange with information embedded in blank document borders

A method for embedding coded information in a coupon with a face value denomination includes encoding that face value denomination value as a plurality of data carrying dot pair patterns where each dot is too small to be visually noticeable. For each page of a document to be rendered, the method includes determining whether the border area is blank. If found not blank the border area is cleared. Each of the plurality of data carrying dot patterns is embedded in the blank border area of the document page. The document page with the embedded data carrying dot patterns is then rendered, where each data carrying dot is too small to be visually noticeable.