I'm assuming you want the gradiant effect to take place across the width of the stroke for the entire length of the stroke (like mixing red on half a brush and blue on the other half and then painting a long stoke that blends from red to blue the entire length of the stroke). The fade set up works from the begining of the stroke to the end of it so that won't get you fade you're talking about. The only way I can see doing what your talking about in Photoshop would be to create a section of gradiant and then use the smuge tool on it. That would be teadious though. I don't know if you have Painter or not but in painter you can control the color of the 'bristles' more. I've never set one up to do a gradiant type stroke (gradating from side to side within the brush stroke) but it seems like it would be possible. If you find something that works (in Photoshop, please post it! I'd be interested in knowing how to do something like that.