7mm Another attempt

[Osgood]

That works!

 

[ullypug]

In 4mm I wouldn’t bother but in 7mm I’d be tempted to go with individual strips. Why not try a test piece? It’s a bit like embossed brick plasticard. Way too deep to represent prototypical mortar course depths but we all use it!

something else I’d look at are bolt fixings. EDM models sell some very cosmetic nice bolt head and washers which I’d look at if I was doing something light railway ish in 7mm…

Bolt heads

 

[Pencarrow]

It also depends on if you're modelling corrugated metal or asbestos sheets. The asbestos is thicker and joints will be more pronounced.