I'm having difficulty with the Blob Brush tool. I have a clipping mask applied to a layer, and I'm trying to pain into it. If I paint touching the object in the layer it works fine, but if it doesn't touch or touches a layer above the layer I have targetted that is the same colour, it will paint either on a new layer, or on the layer above. Is there any way to turn this off? It is frustrating the dick out of me.