To follow up on the discussion of printer resolution in another thread, I just did some test prints of this:
This was my procedure:
To avoid other up-scaling, I sized the image based 600 dpi. that gave me an image that was 9.33 x 7.47 inches. I printed three ways:
1. LR set to 300ppi, firmware set to high quality
2. LR set to 300 ppi, firmware set to highest quality
3. LR set to 600 ppi, firmware set to highest quality.
(I'm printing on a Canon Prograf, so the "normal" software setting is 300 ppi, while the nozzle pitch is 600 per inch.)
I printed on Canon Pro Platinum paper, which is the only fully glossy paper I had lying around. I generally don't use glossy papers, but I figured a glossy paper would be best for showing small differences.
The bottom line: they are very similiar. I had to look at them several times to compare them. However, after repeatedly evaluating them--the last two times blind, with the identifiers hiddedn--I came to the conclusion that #2 produces the best result. That wasn't my hypothesis. My hypothesis was that 1 and 2 would be similar but that 3 might be better. In fact, 1 and 3 are very similar, and 2 has slightly better detail.
On the negative side, I can't explain this. On the positive side, #2 is what I have been doing all along, so I now know that I can just keep doing it.