There's CUPS installed by default. It has a web interface in addition to the
printers dialogue box.
http://localhost:631/admin
sudo apt install printer-driver-all
should install all of the printer drivers in the repo. If your printer still
doesn't work then Trisquel doesn't have the necessary driver, possibly because
no free driver exists.
If you do end up buying a new printer, take a look at h-node
Two months ago I installed on my notebook Trisquel 7 as operating system.
I currently have a Canon PIXMA MG4250 printer; is there a printer driver
compatible with Trisquel 7 available for this printer or do I have to
purchase a new printer?
What are the portable printers compatible with