Artem Burkin
Found your building album, I've never seen this presheding - very interesting)

Ricardo Reis
Yes, I did some experimenting - in every build I try new things; in this case, you will find this a lot in our spanish colleagues - an example can be found in the Diego Quijano's Encyclopedia of Aircraft Modeliing Techniques (from Ammo) called the modulated shading and pre-shading.