The Ice White Door is MDF (Medium Density Fiberboard), but not the old MDF we think of as particle board. It is a compressed hard wood masonite which forms a perfectly smooth finish which accepts the paint better, similar to the paint on your automobile. It is more expensive to produce, takes paint better than hardwood, no grain to show through, and there is no expansion or contraction in this material which can commonly cause cracks during high or low humidity in white cabinets. The box construction is all wood.