Homebrew PCBs

I have been using Laser Transparencies for many years.
For a long time the best for my LJ printers was the 3M Type CG3300
and then I found Apollo CG7060 and it is much better.
3M is good, Apollo is much better and I can do 5 mil line on Apollo but
not on 3M.

Comparing registration from Transparencies almost certainly will be a
problem.
Paper will hold different amount of water and therefore it's stability
is questionable.

I have also found of the three program I use to print artwork when I
Mirror one side
to make the emulsion be closet to the PCB, the registration is always
wrong.
I experimented with not mirroring and found 5mil lines are just as easy
to do.

Preheating the LJ by printing something (text to save toner) on paper
just before
printing the Transparency may help keep the LJ drum at a more constant
temperature.

Hans W