This is exactly what you have been looking for the 30 : 30 Vision 2011 Competition. Cut exactly 30cm x 30cm and 18mm thick HMR MDF.
This substrate is designed to be painted on this sides so there is no problems with size – if you mosaic the sides you might end up going over the competiton requirements for size.
This substrate is : Primered ( sealed ) with two coats of Ardex Multiprime : pre-drilled in the exact place for the ‘D’ Rings and the ‘D’ Rings are supplied too along with the screws. How easy is that !! Already to be mosaiced in the design of your choice for the competition.
Also don’t forget these are terrific substrates just for projects too, not only for competitions.