Make sure your printer is printing is Black and White mode only. If it is printing in RGB, the results will not be the same. You want pure black on your file, and only black and white on your printer.
Also, automotive clear coats will be better than Krylon. Try a rattle can lacquer and see if that helps. If you’re producing a gang of dials, get an affordable 2k clear coat for optimal clarity and durability.
Forgot to add, never sand in a circular motion. That is a wives tale only good for polishing silver forks and spoons. Sand in one direction, rotate 90 degrees and sand again. Then rotate 45 degrees and so on and so forth. You’ll never get it perfectly flat by sanding in circles.
Lookup some YouTube videos on wetsanding or colorsanding automobiles. Use the same technique but adjust for the miniature size of a watch dial.
Thanks for the advice, it's right in line with some stuff I've been reading. It's starting to look like I should do a batch of a dozen or more dials to take advantage of the 2k clear and limited shelf life of gold electroplating solution.
The one difference between the decal dial and automotive process is that the decal texture needs to be obfuscated somehow along the way. I found that sanding the krylon stuff with 800-1200 grit really does the trick for that, but then the challenge is to somehow restore the color depth and gloss look, perhaps with follow up coats?
I noticed this article suggesting that getting the sanded clear is only the first step, followed by polishing, glazing, and waxing. Do you think any of these products would be useful, specifically the Klasse all in one, sealant glaze, and carnauba wax? It all sounds great but the price of these things adds up quick.