Andy made the frame with 2x4s and a sheet of OSB then we used spray glue to attach the foam, added a layer of batting, a layer of liner material (I used a queen flat bedsheet because it was cheaper and I needed the width), and then topped with the upholstery fabric. Andy bought a compressor before we moved anticipating all of the renovations so we used the pneumatic stapler to attach the layers. The final product was heavier than I expected and we still have to bolt it to the bed frame, but it was complete enough to put in place. After a few months of having a blank wall behind the bed we had to get used to the new headboard, but we are both pleased with the end result.
Back of frame.
Attaching the foam and allowing the glue to set.