Many thanks again Diolma! (I didn't get the automatic thread update message mail so I had to check it manually) I've totally forgot that little weed icon...make planes unfriendly; got it!   :-D

I've made some testrenders using your dark strip tut; the drawback is that my original (complex)texture is ruined when I attach the function to the texture color output; it changes to the worse but yes, I get a desired dark/wet strip...that unfortunately costs a change in the original texture (becoming "flat").

I think e-on should implement a simple menu/button/slider for this particular problem for a better result.

Many thanks anyway; your suggestions were very useful and I learned a lot!  /Attila