A beautiful 16" x 20" is now emerging from your printer. When it is finished, set it aside and proceed to the next step.
You have cut a sheet of high-quality watercolor paper to a size slightly larger than your negative. Bring out the chemicals that Willis used in 1871. I use Ron Reeder's process, which is a little different from the "standard" method which controls contrast by varying concentration of one of the chemicals. In Reeder's process, contrast is controlled in Photoshop.
Determine the amount of coating (in drops or "minums") for the specific surface area. (It is all proportional). Combine the number of drops of the palladium solution and the ferric oxalate solution. Usually this is done in a whiskey shot glass. Swirl the mixture (which looks very much like whiskey) a few times and pour it on the watercolor paper. With a brush, work the liquid into the fibers of the paper. This may take a few minutes, depending on the size. Set aside to dry. In this climate, usually about 30 minutes.
When the paper is dry, place the digital negative emulsion to emulsion (as with a normal negative) and expose to an ultra-violate light source. This can be the sun (usually about 8-10 minutes on a bright day) or, as I do, in an artificial UV light source that is, er, predictable. Mine is an old NuArc plate burner that was used in the lithography business several years ago. It delivers well-timed and measured UV light.
The calibration of the process is tricky, but exposure has sorted out to be about 4-5 minutes. A latent image is evident when you remove it the light source.
Place it in a tray and pour the developer over it. Immediately, the latent image becomes vivid and clear (hopefully). Fix and wash the print and hang it up to dry. Within a couple of hours you have a dry and beautiful palladium print.