FSX Specular file - How to create?

Hi,In looking at the default Cessna 172 files, there is a regular texture file and a specular file - which to me looks like a "browner" version. What is the difference, and how do you create this file? Is there a way to modify the texture file to create the specular file?Thomas[a href=http://www.flyingscool.com] http://www.flyingscool.com/images/Signature.jpg [/a]I like using VC's :-)N15802 KASH '73 Piper Cherokee Challenger 180