The check printers I’m familiar with were HP printers that were then heavily converted by a specialized company. You’d feed it sheets if checks that had all of the static information like company name and account information pre printed on them into the printer. From there it was already calibrated to print out the date, pay to, payment amount, and notes in the correct spots with special magnetic ink. Then on order to unlock the printer and allow it to print you would insert a USB key.
the question is worded a bit strange, but I’ll answer what I know. I work as a bank teller and we have sheets of blank checks that we use. it’s a sheet of paper with some perforations and basic information. our logo, “pay to the order of” lines, signature and memo lines, etc. through the customers profile, we can print checks with their information that overlays on top of the sheet and prints out their name, account and routing number, etc.
so the sheets itself just have outlines and universal information all checks need, and then the printer adds on account numbers and names and addresses according to the profile we printed the checks from.
This answer may be old. 25 years ago I used to do accounting software implementations. Part of that was check printing. The company would buy pre-made checks from a printing company. That paper had a watermark bank and routing number etc. I would setup the print job that would match the blank spaces and at the time they used MICRE (might have spelling wrong) basically magnetic ink that would fill in the routing and account numbers and the check serial number.
As far as I know they purchased the blanks from printing companies, actually those small mom and pop shops. I liked that. Because I was paid about $25/hour under the table to carefully make the print job match this personally designed check. Easy money for me.
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