In the radiant blue chamber of the ZPrinter 850, a skull is born.
An ink-jet arm moves across a bed of gypsum powder, depositing a layer of liquid that binds the powder together in the shape of a cranial cross-section. Then the arm sweeps across again, brushing on another thin layer of powder, followed by another layer of liquid, indistinguishable from the first, its imprint as abstract as a coffee stain on a napkin. Watching this process is akin to watching a movie with a slide projector—it’s slow. But after 12 hours and 1,500 layers, a technician will reach into the dust and, like the world’s luckiest archaeologist, pull out an impeccably structured replica of a hominid skull.
Since December, the Smithsonian Institution has printed a few dozen such copies. By April 2017, as part of its traveling exhibit Exploring Human Origins, the institution will have presented 95 skulls to participating libraries across the country, an extraordinary diffusion of some of the world’s most precious natural relics (or at any rate, their facsimiles).
The project—the largest 3-D-printing effort yet undertaken by the Smithsonian’s central exhibits team—vividly demonstrates how technology is changing museums’ approach to art and artifacts. As fragile, rare, or ephemeral objects are rendered durable and plentiful, the benefits of accessibility are pitted against those of authenticity.
The work seen here begins at a Smithsonian vault along the National Mall, where Carolyn Thome, a model maker, uses a scanner to generate a digital 3-D model from a cast of each skull. (The original skulls are owned by foreign museums, and casting additional replicas was not practical. While casting can yield convincing simulacra, it can damage the original.) The rest of the production process takes place at a Smithsonian facility in Maryland, a kind of Santa’s workshop for facsimiles and exhibition scenery. On a recent Friday, in a small room off the main hall, a copy of Thomas Jefferson’s gravestone sat on the floor, and a partially completed 3-D-printed replica of a rattle from Alaska’s Tlingit tribe lay on a table.