A while back I tried to get this effect by scribing and painting combined.
I initially sprayed the building's walls a metallic grey colour using a Tamiya spray bomb, then when the paint had dried, I lightly scribed lines as Dick has. Then I masked off the bottom 8', making sure I had a nice tight top edge along the scribed line, and then gave the walls a second coat of paint. After that coat dried, I repeated the process another 8' higher.
I was hoping that the thicker paint along the top edge of each line would simulate the overlapping sheet of metal, and to some extent, that did work. From normal viewing distance, the walls have three distinct bands due to the lower coats being lighter grey than the highest coat (same colour, just less paint thickness). But the paint edges came out a little fuzzy, when viewed up close.
Next time I try this I will paint the entire wall initially, but on subsequent layers I will only paint a strip about 10' high each time.
Sorry - no photos.
BTW Dick - I like the effect you got by using the pencil for the vertical seams.
Regards,
Ron