Looks like the invoice was printed on a (very old) 9 pin printer. You can count 7 dots in the right side of "a" in Tax and add 2 more to get to the top of "T". I had one once. An EPSON. Darn near bullet proof. It never did die - just became obsolete.
Then along came 24 pin printers and they were, wait for it, "letter quality". And then came the Cannon Bubble Jet and the HP Ink Jet... Quiet. Fast. Reliable.