I don’t know if it’s on purpose or just some collateral effect of the brush engine that some brushes require a “larger” pressure level to even get them to paint any pixel at all.
If that’s on purpose I don’t get why it exists, I think it’s arguable it would be good to be able to toggle it.
If that’s just a byproduct of the engine, I imagine that’s possible to somehow make it so that any brush (any brush that doesn’t paint even without touching) would start to paint even by the slightest touch (the minimal pressure one hardware’s detect), preserving proportionally the pressure curve set-up in the brush settings, of course.
The motivation is solely ergonomy. In an ideal world, the stylus would be able to work pretty much as a felt tip pen, with pressure that’s not even detectable by hardware (at least not mine). This would probably be the closest possible to get to this point, via software.
I can’t even guess what kind of challenge it would entail to implement.
I imagine there must be something along the lines some kind of function that calculates at which pressure the brush starts to actually paint, and then discounts all its pressure settings by the same amount.
The problem might be that many different authors created the brushes, so they all had different hardware and personal preferences. Have you played with the global pressure curve preferences? You could also just edit those brushes to suite your preference. You might even look at the pressure settings for the OS for your tablet, adjusting the firmness settings, etc. . .
The problem with tweaking “global” curve preferences is that it would presumably make brushes that already work with minimal pressure to become hyper-sensitive. It’s not really a general problem, just some brush or another that I find requires some extra amount of pressure compared to others, similar or not, that start to paint some pixels with just barely touching the tablet.
I do try to tweak the brushes to my liking, but it can be quite complicated to achieve exactly that, I guess because multiple things can be affected by pressure and maybe even “custom” input stuff. So instead of just working the same, only starting from minimal pressure, it can become considerably different.
I thought the “pressure” slider (is it new?) would create some “fake” baseline pressure, it would be quite a close approximation to what I wanted (maybe “ideally” it would also allow for a negative pressure, if some brush is hyper-sensitive by default), but apparently it’s not that what it does. I just figured out: it gives “fake” pressure only to devices that don’t have a real pressure input, right? Apparently that’s what happening here, at least.
Just in case someone is also annoyed by this kind of thing, I guess I’ve found out which one is the key culprit setting to be adjusted in order to get at least some pixels of output starting with the minimal pressure input: “opacity multiply.”
In some brushes, it pretty much defines that in order to get some pixels you have to try to engrave your tablet with your stylus, with a good deal of the pressure input set to not have any output.