HPLIP 3.21.8 is here almost two months after version 3.21.6, which only added support for the Fedora 34, Ubuntu 21.04 (Hirsute Hippo), openSUSE Leap 15.3, and Debian GNU/Linux 10.9 “Buster” operating systems, and version 3.21.4, which added support for the HP Envy 6400 printer series, to add support for the Linux Mint 20.2 “Uma”, Manjaro Linux 21.0.7, and Red Hat Enterprise Linux 8.4 distributions.
On top of that, the HPLIP 3.21.8 release adds support for several new printers, including the HP Smart Tank 500 series, HP Smart Tank 530 series, HP Smart Tank Plus 570 series, HP Smart Tank 7600, HP Smart Tank 750, HP Smart Tank 790, HP Smart Tank Plus 710-720, HP Smart Tank Plus 7000, HP Smart Tank Plus 660-670, HP Smart Tank Plus 6000, as well as the HP DeskJet Ink Advantage Ultra 4800 All-in-One Printer series.