In preparing a surface for paint / glue / thermal paste / soldering / whatever, there is one thing to remember. A normal finger print is of similar thickness to cling wrap (0.01mm). A thick (eg post pizza) print, where the ridges are no longer visible, is closer to the thickness of a sheet of paper (0.1mm).
Rule of thumb. If you would you would not be happy with this kind of material on the surface of whatever you are coating, remove your finger prints.
Recently I had to make a series of circuit boards using Eagle Cad.
I spent a lot of time calculating track widths to make sure my circuit board could handle the current I was using.
Then I had to do more calculations for font ratios. so that that all lines were wide enough to work with the silk screening process.
Sick of this; I quickly used matlab to create a few charts so I could look up the answers quickly.
I thought I would share these charts and the matlab scripts, hope they are useful.