Things like font sizes, italics, bold etc. generally come from escape sequences such as those found for the DEC VT100 character set. You need to locate the manufacturer(s) of the printer(s) that you are interested in to get the appropriate control codes to set these attributes. You generally "set attribute" with one command and "unset attribute" with another. The tough part is you have to intersperse your text with the appropriate commands, which is the kind of thing Perl was designed for.

You may also have to be sure the printer is in the "right state" with reset commands before printing. At least invoices and receipts are of a fairly uniform style for printing. In some case you can download crude logos too. We did this with an NEC printer attached to a serial terminal for a County Recorders office system. Good luck.

Diskcrash