Several (many?) years ago I remember seeing, probably in a shed somewhere, a shelving support system that used a horizontal wooden batten, machined into a sort of half round section with a channel running all the way along it. Screw holes at the base of the channel to attach it to the wall, then the shelf slotted (tightly) into the channel and hid the screws. Sort of a not-quite-concealed support for a conventionally-thick shelf, rather than these horrible chunky 'floating' shelves that seem to be all the rage these days.
I've googled my fingers to the bone; anyone know if they're still available anywhere?