I created this texture in InkScape today and exported it with 2048*2048 resolution. There are no dashed lines or the like , but for some reason when the texture is used in the material editor (note: i had masked out the green so only red remains) the image is not like the one that is displayed when the texture is opened in the editor (rightside)
All I can think of is that the mask isnt 100% black/white.
Also, turn off SRGB.
Check the alpha channel of our texture. Alpha transparency is not applied to materials by default so you should be good anyway.
You are necro-ing threads from more than half a year to go.
Check the dates next time.