Hello, thank you for the help.
Billymayday, I did see the link at openprinting.org, but could not get from the information presented there to how I would make use of it.
AuroraCA, I take your point about being able to avail myself of openly available resources. Your answer helped me think about this problem in a new way. I am used to working with Linux by starting with Linux resources and, if you will, working out. Your suggestion strikes me as starting with the outside, what HP as hardware manufacturer offers and working in. I'll remember to use both approaches in future problems.
In terms of where I am, I did find and download the HP drivers and get them on to my machine. Unfortunately, one of the first questions asked by the driver installation is which distro of Linux you are using. The software provides a choice of 11. Gentoo which is what I am using is not listed. At this point I realize I am beyond generic Linux questions, and should go back to the Gentoo Linux resources.