bucket coat render? your not american are you?
Thin coats are usually applied onto insulated backrounds such as eps or phenolic boards
they are very strong and flexible with alot of polymer technology in them. Basecoat applied at 3mm - 6mm is embedded with reinforcing mesh for extra strength and impact resistance, once dry the primer is applied (like paint) to give good opacity on the finish. the finish is pre mixed coloured and comes in a bucket, the application depth is the same as the aggregate in the finish ie. 1.5mm texture is 1.5mm thick on the wall - you dont want aggeragate on top of another it is really scraped on tight as you can and even then it is not tight enough. most people in this country put it on too thick because their arms hurt after 10 mins.
you can finish a solid render job with the texture finish also as an alternative to paint say 12mm render smooth and flat, primed and textured - gives a good low maintenance job.