by 48Rob » Wed Dec 25, 2013 6:53 pm
It can be done with plywood, by fitting sawn pieces of dimensional lumber together, or by laminating thin strips of wood together.
In your photo it appears that the frame was sawn from lumber and placed on a laminated strip.
The joinery is unclear overall. It may be two sets of pieces overlapping and screwed together, or it could be they used splines or lap joints.
Rob
Waiting for "someday" will leave you on your deathbed wondering why you didn't just rearrange your priorities and enjoy the time you had, instead of waiting for a "better" time to come along...