Printing photos using F-Spot Photo Manager

[Geoffrey]

I usually 4x6 photo colour prints using the Windows software supplied
with my Canon iP4200 printer. It's easy and works well. Printing is a
relatively slow process, that is much slower than say printing a text
document as one would expect for a high resolution photo print.
I would like to get the same result using F-Spot. After setting up the
page for size (4x6) and paper type (Glossy Photo paper) I chose
Automatic for Image Quality (I also tried 600x600 DPI with the same
result). The print is noticeably less dense than obtained using the
Canon software and, similarly, less than the image seen on screen.
Why is this, please? What is the experience of others?
Of course I could adjust the image colour intensity but that should not
be necessary.
Geoffrey