MITRA Forum Question Details

​Kristin asked if I'd weigh in here, since I'm familiar with the panels. I wouldn't say that I'm an expert, exactly, but I do know that they are basically MDO (multiple density overlay) panels, sized and primed with multiple coats of gray-toned acrylic. MDO is a sign-making material designed for outdoor use (it's often used for construction signs)--it's plywood covered on both sides with a resin-impregnated paper that gives it a very smooth, grain-free surface that resists moisture penetration. 

The guy that sells them describes the panel construction in a way that makes them sound like a unique thing that he invented, but... it's MDO. I'm not aware of any studies on the long-term viability of MDO as a painting support. I'm wary of plywood, as the surface veneers are basically guaranteed to check on a long enough timeline. 

MDO is covered by a resin-impregnated paper, so you aren't painting directly on plywood, though, and the paper provides some moisture protection. But it doesn't protect the edges (aka the end-grain) which is where much of the moisture uptake in wood happens. The edges are primed, but acrylic primer isn't much of a moisture barrier, either. My personal suspicion is that MDO will be more resistant to checking than plywood, but may eventually start to exhibit the same sort of problems--deep cracks in the surface veneers that could telegraph through the paper covering. But that is 100% hunch. Some of the conservators here might have more info on MDO in general.

-Ben Sones

​Hi Ben and Brian,

My question relates to an earlier post, I realize I'm still not clear about it.  Is covering plywood with cloth before gessoing sufficient to prevent checking?  And is the grain pattern of plywood verneer more prone to checking than the grain of solid wood panels (depending on the cut, I suppose)?

Thanks,

Koo