I use CUPS to manager the printer. Install cups to get it. The default driver for this printer that CUPS chooses does not work! (HP DesignJet 1050c pcl, 1.0 (color)). Instead I installed hplip and printer-driver-hpcups (perhaps only one of these was required) and chose the driver HP Deskjet 1050 j410 Series, hpcups 3.21.2 (color).
I tend to prefer to use “fast draft” quality, which can be set in the CUPS administration options page.
Seems to require the hplip and libsane-hpaio packages. I use simple-scan for scanning. I had to chown the device file /dev/bus/usb/002/005.
If xscanimage or sane-find-scanner report that no scanner was identified then you probably need one of the above pacakges.