How do you size ISO-cp text correctly? i want it to be 1/8" but it keeps coming out smaller on the drawings... Help!

Have you gone into the Styles toolbar for that specific text style and resizing the text to the desired size? 

yes, well the problem is that even though it says it's 1/8 " it does not print at 1/8" regardless of the style settings.

is your PSLTSCALE on or off?  That could also be the problem.

Here is the rub, if you draw two lines 1/8" apart and create text using isocp it does not make the text the size I'm asking for therefore the plotting would be off as well.