Printing
Use the CUPS command-line tools. Printers on the network that support driverless printing (IPP Everywhere, AirPrint; most made in the last ten years) are usable without being added: they appear in lpstat -e on their own. A USB printer, a printer at a fixed address, or an older one that needs a driver is added by the person in Settings, Printers, Add a Printer (slate-settings printers).
See the printers
lpstat -e # every printer you can print to, network ones included
lpstat -d # the default one
lpstat -p # the added ones and what they are doing
Tier: observe.
lp -d <printer> <file> # PDF, images and plain text print directly
lp -d <printer> -n 2 -o sides=two-sided-long-edge <file>
lp -d <printer> -o media=A4 -o page-ranges=1-3 <file>
Tier: confirm. Paper and ink cannot be given back: say which printer, how many copies and which pages before printing. Office documents: convert to PDF first (see the office-libreoffice skill) and print the PDF.
The queue
lpstat -o # jobs waiting or printing
cancel <job-id> # e.g. cancel Office_Laser-12
Tier: reversible (a cancelled job can be sent again).
Default printer
lpoptions -d <printer>
Tier: reversible.
Verify
lpstat -W completed -o <printer> lists the job once the printer took it.