At the weekend I built my open baffles using the 12" Rola full-range drivers.
I used 30mm Pine (bizarrely for a country that grows so much wood, the Pine is imported from Chile) with a Briwax rustic pine stain and wax finish. Baffles measure 900 x 800.
The sound is much bigger than I achieved with the 8" Plesseys. No surprise - the cone surface is more than twice that of the smaller driver.
The footprint is much larger than the other baffle - my partner is not yet convinced that this is a step forward or that it is necessary!