Sheriff-murder 说:
That is the same as DXT5 in Photoshop. FYI.
However, can't get it to work.
They are always visible regardless to me.
DXT5 is a compression method not a format

if you want to use dxt5 compression make sure you save as
Alpha Exponent (DXT5) (and not BC3 or YCoCg) in witch case transparency goes from black - full transparency to white no transparency .
same mat and texture as before but with DXT5 compression

notice how all the darker spots are now transparent. Also if you have an older graphics card that only supports vertex shaders 1.X you may need to switch to DX 7 render mode and down load the dx7 shiny armor fix, my guess is you just saved it with bc3/dxt5 compression though.
hope that helps