I have a Starrett precison level I think is not perfectly flat on the
bottom.
What is the proper procedure for checking the flatness of a part using
a surface plate? For example:
Do you coat the part with Prussian Blue? How, a finger tip, what
thickness?
How do you test it on the surface plate - press it down gently, slide
it, rotate it, what?
How would you prepare the surface plate - clean with alcohol, use a
damp kem wipe, what?
Do you test flatness on different sections of the surface plate?

I hope these are not to basic. Any other hints, tips, cautions, would
be sincerely appreciated.

Gil