My hand writing is ugly, but I didn't feel like typing it out on different layers; sorry if you can't read it lol.
I know I'm not the only one out there that got a little frustrated when trying to wrap my mind around 'Flow.' It's still worded oddly when I think about it. 'RATE AT WHICH PAINT IS APPLIED' just doesn't sound good to me, haha.
But today I sat down and started to experiment with my settings-using only Opacity, Flow, and Transfer's settings which has Opacity and Flow as well-I set each and both to Pen Pressure to see results.
Some people don't know the difference between Flow and Opacity-but one thing's for SURE-Opacity cannot become darker during one stroke no matter how many times you run over your lines (staying in one stroke of course, like scribbling).
Flow can, and will become darker when you run over your same lines again and again until it reaches the Opacity percentage!
So if you have Flow set too...say 3% (super light haha), Opacity to 40%, your lines won't ever go above 40% Opacity no matter how much you scribble over and over in your one stroke. It'll also take a while to get to that percentage as well-because the rate is so low.
I like to have my Spacing (how far apart your single brush tips are) at only 1%. Sometimes the brushes I use are set at the default 25% and I leave them alone though. But for fur, I don't want choppy brush strokes because of spacing issues.
Thought I'd share, and sorry if the file is giant-there is so much more that can be done too. Also-the best thing to learn these little tid bits is to experiment. Change settings around and see what happens-you might find a new setting you like better.