Putting batons onto the back of works

I am developing work for my forthcoming exhibition at Motherwell Concert Hall, and am testing different options for hanging the work. The work has to be attached to wires which hang vertically in front of the wall. I am informed that the fasteners on the wires can be screwed into the back of the work, and so am planning on using wooden batons on the back of the work for the screw to go into.

I have tried a number of methods of putting batons on the work:

- making a sheet of plaster and once dry, glue the wooden batons to the back

- making a sheet of plaster and once dry, glue the wooden batons to the back, then pour plaster around the wooden batons so as to hide them when viewed from the side

- making a sheet of plaster and while still wet, place the batons on the plaster. Once dry, fill the gap around the edge of the batons

- making a sheet of plaster and while still wet, place the batons on the plaster and then pour plaster in the gap around the edge of the batons

- making a sheet of plaster and while still wet, place another piece of cardboard on top of the plaster in order to create a flat surface