I'm using the "sketch shade" brush from the sketch brush engine, and have the issue that lighter colours do not completely cover dark colors. This is how it happens:

On , e.g., a white canvas, draw some black marks with any tool. Select the sketch shade brush, and pick a medium grade color to paint with. Try to completely cover the black marks you made with the gray you have selected.

However much you paint over the black area, a residual darker shade will remain in the area where black was previously.

Am I misunderstanding how the tool works? The blending mode I use is normal, opacity is 100%, I can't find anything that should cause this behaviour.

The opacity of that brush is being modified by the pressure. Open the brush editor with f5 and check opacity. It is effectively at about... 5% opacity.

TheraHedwig wrote:The opacity of that brush is being modified by the pressure. Open the brush editor with f5 and check opacity. It is effectively at about... 5% opacity.

This may be the cause, but it seems odd that multiple strokes seem to stop building up on the canvas. Here's an example.

The black is drawn wit the sketch tool, and the color picker shows it's actually a lightness value of 3.0, not quite 0. The gray is drawn with the sketch tool multiple times, it does not build up any darker than this. The round blob is a reference of what the color at full opacity would be.



In terms of the usability of the tool, would some kind of tweak be possible to how the color builds up? As is, to the user it seems like simply painting over a spot will eventually build up to a fully opaque color, but in reality it stops just short of full opacity.

Yes, you can just adjust brushes and even make personal copies. The presets are mostly there to give you inspiration on how to achieve certain effects so you can adjust these to make nice personal brushes. We have a lot on using the brush engines and making your own brushes in the manual, which you can access via docs.krita.org or just pressing F1.

TheraHedwig wrote:Yes, you can just adjust brushes and even make personal copies. The presets are mostly there to give you inspiration on how to achieve certain effects so you can adjust these to make nice personal brushes. We have a lot on using the brush engines and making your own brushes in the manual, which you can access via docs.krita.org or just pressing F1.

If I understand you correctly, your suggestion is that I adjust the pressure curve for the opacity? Unfortunately I don't see that as a solution: I already have the curve set up so the tool is comfortable to shade with. Increasing the max opacity of the tool makes it harder to use for shading.

Just to be sure we're on the same page here: If I draw with a white, i.e. 100 ligthness (l) color on a black (l=0) area, the color easily builds up. Checking with the color picker, the resulting mark on the canvas is l=98. So it doesn't cover completely, the effective maximum opacity seems to be about 98%. Now, drawing another stroke over this area in the same way, I'd expect the resulting color to be very close to l=100, since the tool gives me a max opacity of 98%.

Maybe related, there's something weird with how the color picker reports the color values resulting from the above. After drawing the white area over black, pressing ctrl to sample the area where the white was applied gives l=100, even though visually the result is not fully white. If I pick a different color in the color picker, and *then* sample the area, the picked color is l=98.

Hello. I experimented a little with the sketch shade brush, and the behaviour described by hulmanen just ocurs in 8 bit per pixel. on 16 bit per pixel it is really easy to cover any color with that preset.

Thank you, artur89sd! That does work around the problem.

It's not a bug. It's also got nothing to do with the sketch brush. It's how the maths work out; the exact same behaviour exists in other applications like Photoshop and Gimp.