How would you go about 'painting' images onto terrain

Basically, the terrain painting that is available by default doesn't fit my art style, i can't have blending of textures. I'd like to have clear borders between different kinds of textures (ex. Grass and Dirt).

I need to paint or print onto the terrain a full texture, not like the wallpaper (repeating) effect that it has by default.

I have made a few Unity Extensions for myself already, and I'm planning on doing one for this project but....

I don't know where, or what i should be doing to get this effect. I've done lots of googling trying to find possible leads and I haven't found much. Any help would be greatly appreciated

Thanks, Tristan