The following instructions were kindly provided by David Berlow:
Aside from the argument of terms, and what is Italic, if you are making a sloping style to compliment a non-sloping style, here is the general start to a sans serif design.
All ascents and descents, x-heights, cap heights and figure heights stay the same. (that’s the good news).
The widths are between 92% and 96% of the non-sloping style, the main stems are 94% to 98% of the non-sloping style. The actual percentages you choose are ball-parked by the overall width and weight of the source, but depend ultimately on the eyes in your head. The reason for this is that the sloping of a style makes it wider, and heavier to the eye, and you need to fix that first, before you even slope.
After you do, (8-11 degrees according to taste, size of use, and speed of traffic, you have lots of curves and diagonals to correct:
Curves between 4 and 5 o’clock and 10 and 11, you need to push out, between 1 and 2 o’clock, and 7 and 8 o’clock. pull in.
The diagonals fall into two disturbed groups as well. The ones that, in house framing, would have stopped the slope from happening, need to be thinned, those that helped push it over need to be thickened.
Then, you have to choose whether you’re going to put all the points on extrema, and if so, you have to re-digitize, or if you use the green gem in FL to fix it up for ya, you’ll want to make a copy to the mask beforehand, so you can see where that tool fails.
Spacing should be about the same as the non-sloping style and you should be ready to proof…