By printing documents and other objects with machine readable indicia, such as steganographic digital watermarks or barcodes, a great variety of document management functions can be enabled. The indicia can be added as part of the printing process (after document data has been output by an originating application program), such as by printer driver software, by a Postscript engine in a printer, etc. The indicia can encode data about the document, or can encode an identifier that references a database record containing such data. By showing the printed document to a computer device with a suitable optical input device (e.g., a webcam), an electronic version of the document can be recalled for editing, or other responsive action can be taken.