Sometimes in discussing how accurate this that or the other thing needs to be someone will make the observation that "a line shift of 30m at 1:1million scale is less the width of the line itself when printed, so, no worries". That's great! For that map that is, but what about this map which will be printed at 1:25,000?
This got me thinking that it would be useful to have a quick reference chart of "how thick is an Xpt line on the ground at Y scale at Z dpi?". A bit of searching reveals no such beast readily available online, so let's fix that!
I suggest a base line of
0.2 pt and
300 dpi since in offset printing that's the thinnest reasonable colour line and standard dpi.