Hopefully these didn't you keep you there rocking for 20 minutes, Bertil I think the Fomabron gives a great look but I find it best with simpler subjects, with less detail.
If you look at my "Flower" lith print you can see another sort of example of what is possible to get from the paper. The scan only halfways represents the actual print, but... as an idea. http://www.apug.org/gallery1/showimage.php?i=55343&catid=member&imageuser=3385 This was the third print in the batch, the first one had a snatch point at about 3-4 minutes (don't have the notes handy).
Thank you for the nice comment about the print, Bertil! The temperature must have been at least 40 degrees and the dilution was 25 ml A and 25 ml B solution of LD20 in 900 ml water (this is a print made on 18x24 paper. about 16x16 cm) with no old brown. More or less constant agitation. I do this in darkness, prefering to check the print and the time with a small red light now and then.