How to add an HP printer from command line?

[Masao Kitamura]

I'm trying to add printers via Kickstart/Preseed to multiple
installation clients on Ubuntu Desktop 10.10.

Kickstart/Preseed works fine and I can run any script at first boot by
editing rc.local, but I'm not sure how the typical printer setup GUI
adds printers.

I've run the GUI like this:

# system-config-printer --debug

...to see what commands it could be calling, but there's a lot of
output and no obvious system commands.

I've also tried various forms of lpadmin:

lpadmin -p hp2055dn -E -v lpd://hp2055dn

(based on the settings I see when I add the printer via the GUI and
check the properties)

,,,but I have not been able to add a working printer by using lpadmin.

Printers I'm trying to add:

HP Laserjet P2055dn
HP Color Laserjet 3500

Thanks,

Masao