$selfillum not working

Hi there
I want to make a part of a texture to glow in the dark with $selfillum but I just can't get it work.

First I tried to compile the texture with an alpha channel but gimp either gives the immage no alpha channel at all or only the glowing part is on the texture, everything else is transparent, no informations of the original texture.
I followed a lot of tutorials closely so I thougt something is wrong with gimp. I thought that doesn't matter since I can just save a seperate texture which will be used with $selfillummask...

So what I have is:

"LightmappedGeneric"
{
"$basetexture" "/lights/Tlight02"
"$surfaceprop" "metal"
"$selfillum" 1
"$selfillummask" "/lights/Tlight02alpha"
}

the basetexture is the normal texture and the selfillummask texture is transparent, only showing the parts which are supposed to glow. But it still doesn't glow. What am I doing wrong?

While I didnt figure out why $selfillummask didn't work, I managed to add the alpha channel with gimp without removing the rest of the texture. Appearently the channels in gimp don't work as intended when I open the image with gimp, instead I have to open gimp first and then import the image. No idea why but whatever, texture has some nice glowing parts now.

Nope, that's for models. It works perfectly fine with LightmappedGeneric since I just want it on a brush. I figured it out how to get it to work as I said in my previous post.
But perhaps selfillummask only works with UnlitGeneric.

Hey good that you mention UnlitGeneric, tested it a bit and while LightmappedGeneric works perfect for most of the textures I wanted to glow, UnlitGeneric also made it work for a transparent textures.