Comment 2 for bug 447961

I have the same problem. The CUPS documentation says the default cpi is 10, but it looks like the cpi scaling is off.
If I print with lpr using default settings, I get 6 characters per inch.
If I print with lp -o cpi=10, I get 6.25 characters per inch.
If I print with lpr -o cpi=17, I get 10 characters per inch.
If I print with lpr -o cpi=20, I get 11.8 characters per inch.

So it's not just some scaling factor. But in any case, if you want the old 10 characters per inch, try lpr -o cpi=17. Maybe you can use lpoptions to set this as a default for every printer you have.

lpoptions doesn't seem to be able to set systemwide options (at least, the man page doesn't mention it). man lpoptions says options are set in /etc/cups/lpoptions, but that file doesn't exist on my karmic system. Nothing under /etc/cups seems to have "cpi" in it. Where is the default supposed to be set?