Where do you find 1 1/8" and 1 1/2" MDF?
It was donated to Habitat for Humanity. I bought a bunch of it for cheap and it's really good stuff, too! I'm all out of it now, though.
Depending on where you live you may be able to find 1 1/2" MDF locally. Or have it ordered for you. The thickest MDF my suppliers stock is 1 1/4", but I think they can order 1 1/2". Apart from the stuff I picked up I've never seen 1 1/8" anywhere else.