Fade Size

[Espermaschine]

I tried to stroke a path with a Fade Size Brush Dynamics, but the result of the Spacing is inconsistent.
On the left its 100, while on the right side its 110 as expected.

The path/fade length was determined with Path Summary from ofn-path-edits.

I get the same results in 2.8 and 2.10. Is it a bug or am i missing something ?

   

[Ofnuts]

Not sure it's "inconsistent". From a developer's standard point, the spacing is the distance between two centers. And this distance is  computed using the size of the brush that was just used. In the left part, the size of the bruhs increases, so the spacing is computed using the size of the smallest of the two brush strokes, and you had to set the spacing to 110% so that the next brush stroke is far enough to not overlap the previous stroke. On the right part the size decreases so the spacing is computed using the biggest of the two and therefore leaves to much room for the next stroke which is smaller.

So you have to make two paths starting in opposite directions from the center and stroke them in turn, with dynamics that are a just a decreasing curve, and a spacing smaller than 100%:

   

As a side note, I have the gut feeling that a straight curve means that each stroke is not going to be exactly N% smaller than the previous one. In other words, a constant spacing ratio could require a non linear decrease of the size if you want circles to be exactly tangent.

[Espermaschine]

I have played with this effect in the past and i could swear it didnt come out this way, but maybe my memory fails me.

What i find confusing is that you could use this curve with Pressure to get the tapered stroke people need for digital drawing.
Or maybe it doesnt matter because for drawing you would use a tighter Spacing.

I was thinking to use this effect for artwork including a "decorational pearls" effect, but if it requires a split path its too complicated.