I built this crib for my grandson (Tristan) and used walnut as the hardwood with 1/2" plywood inserts (painted to match bedroom walls) in the back. The crib rails are all done with mortise - n - tenon joinery as are all of the rail and stiles. The bed used knock-down hardware for connecting sides and ends. Six coats of MINWAX water-based polycrylic was used for the finish. This was the 7th crib I built for my grandchildren (7 different children received one) and 14 grandchildren have slept in these cribs so far.