Many bronze sculptures are editioned: a mold is made from the medium in which the sculpture was first formed (clay, plaster, wood, etc.) and then, via that mold, a number of wax replications of the initial object are made. (These are usually identical, although some alterations and variations can be made at this stage.)

Then follows the lost-wax process of casting: another, different kind of mold is created around each wax, and it then goes into the furnace, where the wax burns out and is "lost."

Next, molten metal is poured into the hollow mold. By this means the image is replicated in bronze. Each of the bronzes formed in a single edition using the initial mold is termed an original, as the clay stage (usually) and the wax stage (always) no longer exist.

In addition to being "original," the bronze trees, Moebius strip sculptures, ruins and boxes made by Amy Bright Unfried are also "unique." Each is the only one of that particular subject or design, just as an original painting is the only one of that particular design. Her tree sculptures originated with small found branches, each of which was unique. The paper and wax "ruins"compositions are each individually constructed.

Similarly, there is only one of each Moebius strip, knitted (or crocheted) and infused with wax, formed to a unique composition, and cast. In essence, the compositions that go to the foundry bypass the initial mold step used in editioned bronzes. That mold permits the creation of multiple identical castings. Here there can be only one.