Digital negatives are used in making contact prints with an inkjet printer. How can I do this with a Canon 9500 II printer?
A good tutorial on making digital negatives using The Gimp. A free image editing software platform.
You can make them on your computer and then print using any printer you have. Not sure why you mention your printer? Maybe some printers have this option built in?
You mention using a Canon printer - Canon uses dye-based inks and Epson generally pigment. Pigment prints are better than dye-based for blocking light, and depending on the process that will be important (e.g. pt/pd printing or albumen)
The best solution is to experiment with what prints work best for you once you've got your image files made. It will come down to tweaking to suit your printer and aesthetic tastes.