HodgmanRichard Macro Focus Stacked 0.5mm
The app DOF Calculator shows that at f/5.6 and 7 in from the subject my 100 mm lens has a 0.5 mm depth of field, so I decreased the spacing between shots to 0.5 mm.
Six images at 0.5 mm intervals gave the data needed to give detail on the pillars. The rings around the nail holes were not well resolved by Photoshop and would take an hour or so to fix manually by adjusting the masks on a couple of layers. I submitted this for the class.