Yesterday I tried to use a painted shader for blending a texture. I start painting, stopped it, used the painted shader as blending shader and rendered. But the texture was blended in stripes on the terrain. Then I started the painted shader again for correct and optimize it, but that wasn't my painting!? Everything was stretched - so I tried again, but with the same result.
Today I created a new painted shader for testing - with the same effect.
paint1.jpg is my painted shader.
paint2.jpg is the painted shader after stopping and starting again (without doing anything else between).