I know that ‘printing’ a PCB layout (rather than a gerber plot) is not the most common thing, but I think it has uses: verifying pad and component spacings maybe, or printing to show someone else how the layout is looking.
If I try this for double sided layouts, it seems rather random whether the top or bottom copper tracks appear top most (and therefore visible) on the print. Even on one board I usually see a mix. This is particularly annoying if the bottom is largely ‘fills’ as top tracks often disappear completely.
Is there any way to control this? It seems to me if you set suitable colours (like a lightish grey for bottom copper and red for top), the printout could look very good - but its spoilt by this random top shows/bottom shows issue.
It may be affected by which layer is the “active” layer in PCBNew (i.e., the layer that would receive the trace or graphic if you started to “Place Trace”). May also depend on whether the layer is currently visible in PCBNew.
I use “Plot” rather than “Print”, so only one layer appears on each page. (I wish I COULD combine two or more layers on a single page!) However, I often “Plot” PDF files, then print them at 1:1 scale, and use the image to gauge the mechanical interfaces to things like mounting holes, connector placement, etc.
Hm… my use case is manual assembly, but there I only need one side at a time, either top or bottom.
For that I made me a special pcbnew ini file, that has got the colors of the layers set so they appear just right on a black&white laser printout.
As for layer order in the print… I don’t try to make sense of it (anymore).
If you need full control your only hope is either some gerber viewer that let’s you print stuff over each other and allows this kind of ‘tweaking’ or you look at the source and try to figure out the print code and put in some modifications.