Thank you. I do not use any rain brushes. Create a layer. Paint it black. Go to Filter, click "NOISE" add Noise. Gaussian Blur: 400%. Micronumenic. Then go to Blur. Motion Blur change the settings however you want. Then go to Image, levels and move the levels until you give the black layer a kind of rain look. Then go to layers and change the look from "normal" to... I don't know "clear". And there you have it you've got rain!