As the catalog on Anderson & Vreeland shows, the KM series comes in a variety of thicknesses, and the plate is harder after processing than other types of plate.
The KM 73 plate can reproduce halftone images up to 200-lines/inch according to the documentation.
The random aquatint pattern imaged on to the plate to the left in the second exposure was accomplished with an 1800 dpi screen purchased from T and R Graphics in Colorado. They worked with Jon Lybrook to create the stochastic, aquatint screen specifically for his use in polymer photogravure. Jon suggests asking for Rick Williams and mentioning his name.
The ink I am using is a classic Universal (Soft) Black etching ink #55981 from Charbonnel. It is available from a number of suppliers. Graphic Chemical and Ink Co. also make a respected line of etching inks. Etching inks have a consistency and pigment designed to work with well in how the ink is lifted by the paper. There are many varieties of black ink from each manufacturer, and many varieties of ink (an enormous color range is possible which is one of the primary attractions of this process for me).
On the right you can see the same magnified area of the plate after inking. The numerals are raised and were cleared in the wiping - the black areas are textured from the aquatint exposure and hold the ink for printing.
I am musing that the photogravure process is demanding and a bit more complex than other alternative processes as you not only have to produce a well-expressed print (the plate) from the original image (what would for other processes be your negative) - but then print that plate as a traditional etching printer would. I've seen references to master plate makers distinguished from master printers - and Jon Lybrook recently made a notation on his excellent site describing polymer plate photogravure that:
The better plates we produce, the more an expert level of skill as a printmaker is required to render the subtleties and details contained in the new plates.
If you were looking for an alternative process to pursue that had a depth and potential for a lifelong learning experience, this may be the process for you!