The MDF door features the same 45 LB density core as the wood Doors. Many other companies use a solid MDF core for their styles and rails that can warp especially in high humidity climates.
Other companies are even forced to go to an engineered core for pocket doors in order to keep them stable.
Koch is said to be one of the most stable MDF doors on the market The lag bolt construction becomes even more important with an MDF Painted Door - The last thing you want is that paint joint popping open and coming apart.
A Solid popular wood edge is standard on all MDF doors automatically ( better to screw and hinge too)
Also a solid wood edge band on outer and inner stile edges.
Very high quality primer applied to all MDF doors . Available up to 10 foot tall on fire rated doors and up to 5 foot wide.