I've updated the TF2 classes sprays with a VTF file instead of a TGA file. VTF supports transparency(TGA does too, but I'm having a hard time to figure out how...), so I've given the sprays more of a poster feel as well, by adding scratches and rough edges. Personally I think these features make the sprays fit more in TF2's comic-like style environment.
The previews shown on deviant art may look a little weird for some (the edges look crappy sometimes, mostly because DA adds shadows or a white background behind the preview images) But I can asure you they will look just fine ingame!

I hope you like the update!