Hello !

I think there is a big issue with the flow setting for brushes :

Indeed, this is what I get with the most basic brush :



As you can see, with 100% opacity and 50% flow I get a darker result with a low pen pressure than with 100% opacity and 100% flow, which is not logic because the flow is supposed to be the ink quantity on the brush, so the result should be lighter and not darker... When I change the flow setting while painting, it messes up my values, etc...

because the flow is supposed to be the ink quantity on the brush

Maybe in real world. But in digital art; the term has been borrowed to describe another behavior; and that since decades.

The Flow parameter is just the way the opacity of each dab (the shapes that build your stroke) is described in digital art.

At 100% all the shape merge together and allow opacity to do something special: opacity pressure variation on the full stroke with smooth transition of opacity.

But under 100% all the dab get their own opacity again and build up together. If you have a very low spacing (so; meaning many shapes overlapping) the opacity build up quickly to black. That what your screenshot describes and it is correct.

Thanks a lot Deevad for your quick reply !
(It's off-topic but I have a lot of respect for your work !)

Hum I guess it depends on the software, because if I understand well what you just said then in Krita if you decrease the flow parameter the stroke for each dab depends on pressure but the "stoke opacity" doesn't any more (even when it's activated in the brush options...), whereas in Photoshop for example you can somehow get a softer result if you decrease the flow while still conserving smooth transitions of opacity...

I'm currently following a concept art and illustration online formation, and sometimes it gets a little frustrating because Photoshop is used in every lesson, but when I try to adapt with Krita it's sometimes difficult to get the same results for brush settings
Could you please give me some advice about that ?

Thanks

You need to play with the pressure curve of Opacity and Flow and you'll probably match the same type of results (but not with the same digits).
You can see how Basic-4 Flow Opacity is designed on the default presets to use a dynamic flow curve plus a opacity one.

Thanks again !

Ok ! I'll look at "Basic-4 Flow Opacity" then ! ^^

I'm sure with some time I will get more used to it

I pointed something about how Krita handles Flow out a while ago. It's a bit different compared to how other programs like Photoshop handle it.

You can check it out here ... https://forum.kde.org/viewtopic.php?f=288&t=136165&start=15

Hello andreasresch,

After a few tests, I think the settings should be something like that for the same type of result :

Photoshop -> x% Opacity and y% Flow
Krita -> x% Opacity and (x% * y%) Flow

Example :
Photoshop : 50 % opacity and 40% Flow
Krita : 50% opacity and (50% x 40% = 20% Flow)

I don't have Photoshop, could someone please confirm that ?

It works but it's more complicated and you have way less control since you have to always use very small values for flow (unless you want the opacity to build up very quickly...) ^^'

Hey.

If that formula is correct you never have completly individual control over Flow, which is a pity.

Well I think in Photoshop the Flow setting already takes Opacity setting into account, while in Krita it is completely separated (which seems a little illogical to me, because a dab can never be darker than the max opacity anyway...)

I'm not 100% sure the formula is correct because I don't own Photoshop to verify it (and I don't want to download the trial version just for that) but from the tests I made to adapt my formation to Krita it seems this is how I get the same kind of result, so I think the formula should be really close of this.

-> If I'm correct, if Krita simply was to multiply its current Flow formula by Opacity setting, you could have the same precision you have in Photoshop, because Flow would represent a percentage of the CURRENT Opacity instead !