printer freedom
"All modern printers have or utilize some non-free software. Some require you to run it on your machine (proprietary driver), some require a free or proprietary driver, but that then it downloads a non-free component and uploads it to the printer and executes on the printer (some HP models), and some just have the non-free firmware on a chip already that is built into the printer. This has been accounted for and no such non-free software is required at the OS level or needs to be uploaded to the device. The device still has non-free firmware obviously, but is contained solely in the device itself (it is probably always the case that this non-free firmware that is contained solely in the device on a chip can technically be flashed regardless of manufacturers providing updates or not, but given it is proprietary nobody other than the manufacturer can provide said updates)." -- Chris
Tracking dots
Some printers mark each page faint yellow tracking dots. These dots are not visible to the naked eye. You can see them under blue light, or by scanning and magnifying the scanned image. The dots represent the printer's serial number, and in some cases, the date.
The EFF keept track of printers that do/do not employ this method of serreptitious tracking:
https://www.eff.org/pages/list-printers-which-do-or-do-not-display-tracking-dots
https://www.eff.org/issues/printers
Drivers
http://h-node.org/printers/catalogue/en
HPLIP
“In computing, the HPLIP (HP Linux Imaging and Printing) project—initiated and led by Hewlett-Packard (HP)—aims to ease GNU/Linux systems' ability to interact with HP's inkjet and laser printers with full printing, scanning, and faxing support. As of 2013 the supplied printer-drivers support a total of 2,080 HP printer models; many of these are free and open-source (FOSS), licensed under MIT, BSD, and GPL licenses, but others require proprietary binary blobs. The project intends that HPLIP work in combination with CUPS (Common UNIX Printing System) and SANE to perform printing and scanning respectively.” - HPLIP on WikipediaHPLIP provides both a graphical interface and the respective printer/scanner drivers.
Non-fully compatible printers that use HPLIP
Here is the list of printers that use HPLIP and require or have optional binary plug-ins as well as the purposes of the plugins. In other GNU/Linux distributions, the command hp-setup will attempt to install the binary plug-ins, when the user is setting up the printer and he will be given the choice to accept an agreement (reference) before installation, but this is not the case for Trisquel (reference].References
- Devices Supported by HPLIP on the official website;
- Diagram of the system interaction with HPLIP as well as other technical information;