Late in 1959 Indiana began making freestanding constructions out of wooden beams salvaged from buildings on Coenties Slip that were being demolished. He called these works “herms,” after the hermae pillars that marked boundaries and served as milestones in the ancient world. In his journals he detailed how he modified these works over the years, attaching discarded wheels and painting shapes, single letters, and numbers on them using die-cut, brass stencils found in the artist Lenore Tawney’s loft. The artist began working on Zig in 1960, and was still modifying the work in 1962, as noted in a journal entry dated August 6, 1962:
“Thirdly, to another old soldier, ‘Zig,’ formerly Zeus, which I altered by imposing black rings on the two yellow orbs on the reverse side, possibly with the intention of adding numbers to these, probably two and five if I do.”