Many thanks for your support, Bud, Guy and Rick, it means a lot to me!
A few days ago I decided to make myself happy and got me a new airbrush gun, the Harder & Steenbeck Infinity. It is a great tool, but I still have to gain practice with it.
I played around with it today and tried to make preshading on the lower surfaces. I used Drooling Bulldog Umbraun, which works great even with the 0,15 mm nozzle (hope this is the right word...) thanks to the very fine pigment.
Afterwards I took 1500 sandpaper and slightly sanded the ribs to let the white colour show through.
Will see what it will look once I give it a coat of canvas.
Cheers
Ondra