Which option defines the brush pressure sensitiviness?

[markw]

The Pressure setting in the Settings panel dictates both how deep into the canvas media is pushed and the max width the tool head can “splay out” when using a soft headed tool like an Oil brush.
The cursor, when in Outline mode, will indicate an estimate of this potential max width of a stroke.
Theoretically at 100% the head should be at its widest but in practice when using a pressure sensitive tablet there is still a little leeway for the head to expand & contract slightly.

Regarding the first screenshot, I can’t reproduce those tapering strokes that you have got when trying either of the settings you show in your two screenshots And nor would I expect to!
A possibility though, if your tablet’s preferences allow you to edit it’s pressure curve, is that your tablet’s pressure settings may be unduly influencing ARV?
But if that were true, then I would have expected to see very similar results in the second screenshot too? So it may not be that…?
If you restart ARV and/or the computer dose the brush still respond in the same way when using the settings as seen in the first screenshot?
I’m wondering if perhaps ARV has just got a bit “confused” when making those blue strokes? (Yes, I know I’m clutching at straws here!)

[cinematik]

Regarding the first screenshot, I can’t reproduce those tapering strokes that you have got when trying either of the settings you show in your two screenshots And nor would I expect to!

Do you mean that your oil brush does not respond to pressure in terms of stroke width? I.e. when you press gently the stroke would be thinner and if you press with twise as hard, the stroke would be thicker. Is it true?

I played with AR input device settings but didn't find much differece if any while switching on and off `precise tablet`, `use realtime stylus`. Maybe the issue with stylus tip. The model I use has so named spring-loaded tip. Does your Intuos stylus has the same spring-loaded tip? Or the tip you use does not bounce when you gently press it into tablet? That way, maybe when I release pressure the tip reduces the pressure even further and as a result - that sharp stoke ending.

I cheked out my tablet driver and reduced its sensitivity slighly, as a result - stroke ending is not so sharp but still isn't perfect. When I reduced tablet's sensitivity to its min value the stoke ending looks like a step, i.e. even worse.

[markw]

Yes my pen has pressure sensitivity. And yes the tip is slightly springy!
Now, after playing with my pens pressure curve some more in the tablet’s preferences, I find I can get similar results as seen in your first screenshot with the brush settings shown in it.
This new pressure curve response though is now applied globally to all tools in ARV, which is to be expected.
Which means, when switching to your second set of brush settings as seen in your second screenshot, that brush now also gives similar results as to the strokes seen in the first screenshot.

To get the second brush to produce the strokes you’ve shown in your second screenshot, I have to go back into the Wacom’s preferences again and reset the pressure curve back to how it was before.

So as I say I’m a bit stumped as to how you got such differing strokes just by altering the Oil brush’s settings as shown.
What doesn’t happen for me and shouldn’t happen is for the tablets pressure curve to change when altering brush settings in ARV.

The first screenshots here is of how the Oil brush works for me using my usual pressure curve and switching between the two different Oil brush settings shown in both your screenshots.
The second screenshot is after playing with the pressure curve in the tablet’s preferences and then once again switching between both your shown Oil brush settings. Like yours the strokes are going from top to bottom.