The Plaster rail is by far the most discreet picture rail ever made. It's steel profile is plastered in after the plasterboard sheeting phase during construction.
When completed the plaster covers the profile and fixings leaving a simple 5mm gap horizontally across the top of a wall. Hangers are then inserted anywhere along the rail in the normal way.
This system is perfect for a modern design with minimalistic appeal. The optimum height of the rail is between 2.3m to 2.6m from the floor level when a standard height ceiling exists or anywhere up to 3.1m if there is a particularly high ceiling.