Depends on when "back in the day" was; even in the mid-to-late 80s, especially if you were on a multi-user system, on BSD 4.2/4.3 local and networked printer access went through the Line Printer Daemon (still available on the BSDs).
For PostScript printers, there was a filter application (provided by Adobe) that would turn plain text (without the %! magic) into PostScript.
For PostScript printers, there was a filter application (provided by Adobe) that would turn plain text (without the %! magic) into PostScript.