I can almost guarantee it is MDF, but whatever, it doesn't matter to me. I find it dubious that they would use particle board for a table that is generally lacquered, as all of their other lacquer work tends to be on MDF. That goes double for the clean miter. I don't even think lower quality particle board is paint grade. Same for veneer. For melamined stuff, yes. I am not able to feel the length and continuity of fibers when I knock on wood. YMMV.