Photoshop CS2 Question - Brush transparency?

[noparlpf]

Say I have a brush that looks like this:
http://i1204.photobucket.com/albums/bb416/noparlpf/Untitled1_zps0knry7cu.png

And I want it to do something like this:
http://i1204.photobucket.com/albums/bb416/noparlpf/Untitled2_zps5nm0n5ce.png

But it does something more like this:
http://i1204.photobucket.com/albums/bb416/noparlpf/Untitled3_zpszyl4gz8m.png

Which still looks kind of neat, but it's not what I was going for. I also tried making the white bit FFFFFD instead of FFFFFF on the image I made the brush from, or making the active background color FFFFFD while drawing, but neither idea worked. I think I'm coming at this the wrong way...for one thing the back end of the brush is going to keep drawing even if the white erases the black bit in the previous stroke. I have no idea if what I want is possible or how to go about it. Any ideas?

[Alent]

Just saw this, sorry if you've already got it figured out: The trick to what you want to do is to think backwards.

Photoshop brushes can't reliably be more than one color. So what you'll end up doing is making a layer for this, painting with a solid white brush, and then giving the layer the "Stroke" blending property, and customizing your black outline in the layer blending options.

You CAN do this in Adobe Illustrator, where there's literally a tool designed to do exactly this, but it's a drastically different program.