How to smooth a render target "brush"?

I recently started making a customized fog of war type system. Everything seemed to be going SMOOTHLY until I started drawing the brush itself to the render target. When using an additive brush, the smoothness lessens. When using a translucent brush, it leaves “artifacty” looking areas from where the texture is drawn over the previous textures. I would like for it to be smoother like the second image, but it would need to be additive for the images not to override each other… or am I overlooking something?

Using “Additive” brush (ignore the FPS, I was running 5 different programs at the time):

Using “Translucent” brush:

Never mind, I found a viable solution to my problem and no longer need assistance.