Hi Jan @vsete ,
I didn’t know these shortcut keys for Brush Size, I always just use F to change the Radius.
But the [ and ] keys Scale the Radius by 0.900 and 1.111 respectively, so it’s not additive (incremental), but multiplicative.
As far as I know, you cannot change that (unless you change Blender’s Source Code), although you can change the Scalar values if you want.
But because the Radius is in Pixels and always a (positive) Integer, you probably always get a different result going up or down (due to rounding).
