Ok, this is nothing serious, but if anyone can offer adice, I'm grateful.
Pix taken on a SLR camera recently looks great when I'm viewing them in Photoshop, and they print ok on 6 x 4 size paper, via a new Hewlett-Packard HP7450 printer. If I go up to A4, they're grainy as heck (even some of the digi-ones)! I've tried dicking about with resolution sizes, and keeping the file size to around 1-1.3M. I get the same results with the HP software.
I'm still finding my way around Photoshop and PC printing, so any help is appreciated.
Try setting the resolution, in photoshop, to the max res which your printer will produce. Then print at that setting. That should be the best print that you can produce with that image, but if you start with a low res, it may not be too good.
PC Advisor have had articles on this which you might find in the archives.