i noticed that some brushes like gimp have a white background. Why is that and how do i get rid of it?
That’s the way gimp brushes are defined. They still work as a brush mark: the white is interpreted as transparency.
i thought they were png images. So you can only use gimp on a white background than?
If these brush tips are pure black, without shading/brightness gradations, then you can easily convert them to PNG’s. To do this, simply load the brush tip in Krita as an image and use the “Similar Color Selection Tool” to select the white in the image, then cut it out using ‘‘Edit’’ >> ‘‘Cut (sharp)’’, then you can save the rest as a PNG with transparency.
However, if the brush tip has many shades/brightness gradations, you have to try to preserve as much of that brush tip as possible with the Similar Color Selection Tool settings, a thankless task which would be too cumbersome for me, I’d rather put up with the white of the GIMP brush tip.
No, for .gbr brushes, the white background is interpreted as transparency.