Correcting for an upside down section while tracing
One of the most frustrating situations you can encounter when mapping serial sections is to realize after the fact that the section you have been mapping was mounted on the slide upside down.
To remedy this problem:
If this seems confusing, imagine a loaf of bread with a heel. You want to put the heel back on, but it is upside down (that is, the crusty side of the heel faces the loaf).
See Flipping a single section with a completed tracing if you have already completed tracing a data file and notice that one of the sections appears to be upside down.