Hi!
I found an issue with some brushes:
As you can see in the image below, painting seems to affect the color below up to the boundaries of the square of the brush size.
If this is not the right place to post issues please let me know.
Cheers!
Pablo
It’s the right place to raise issues 
This happens with 16-bit float and 32-bit float images and the effect goes beyond the square of the brush tip texture image. That can be seen above with the faint yellow ‘filaments’ beyond the dark red rectangle area.
Looking at the brush tip .png, it doesn’t seem to be a problem with faint residual content in the tip image.
@RamonM will probably be interested in this.
Can you publish the file? i want to see what happens there. Thanks
Do you require a .kra?
Anyway it’s easily reproducible, just paint something as background and then with the WaterC Basic Round-Grain for example, paint over and that’s the result of the image I pasted above, nothing else
Hi!
I’ve been testing brushes and found out the problem.
The problem seems to be generated when selecting a predefined brush tip with Substract blending mode.
It happens with other brushes, not specifically the ones I mentioned above, I’ve been able to reproduce the same behaviour with Basic-5_size and Ink2-fineliner.
I tried the Wet-bristles, which has a different brush engine, also in Substract mode but the problem doesn’t happen.
Hope this helps, let me know if you need any other information.
Cheers!
Pablo
I will test it as soon as I can but if the error is only reproducible with 16 bit depth then is time for coders.
Wet brushes with color smudge brush engine can’t use the subtract mode in the masked brush feature as I know. Can you show us some screen captures?
I was asking for the .kra file to use the same resource. Thanks
Hi,
You can get the file from here, please let me know when you did so I can erase it.
https://drive.google.com/file/d/1PR0s3DQyIFZGeglkER83CCNQdtYBfUO_/view?usp=sharing
Also, regarding the wet brushes, you’re right, it’s the blending mode for the brush I changed, not the brush tip option ( I’m sorry I don’t exactly know the difference).
Pablo
https://bugs.kde.org/show_bug.cgi?id=424210
This is where @wolthera has told me the bug is reported. (thanks) .
i have donwloaded the file already .Thanks
ok i have tested the brushes and yes. Confirmed. usually i use 8 bit integer to get more fluid brushstrokes, so never noticed that. Thanks a lot @pablo and @AhabGreybeard. Now is time for coders and his great and amazing knowledge 
