is it possible to paint custom terrain textures on top of biome texture spawner?

[abdul]

i'm using a custom texture spawner for a custom biome, but i also need to paint some custom textures shapes in some places. i tried doing this, and it works, but if i run the spanwer again it clears my custom painted areas. is it possible to preserve the custom paint areas and apply them on top of (or after) the spawner applies the textures?

[Bryan]

You could use a distance mask to control the spawning or height masks. 
Then make sure that you spawn local not world.