P is a glass artist. P began experimenting with jellyfish sculptures in the glass-in-glass medium and, in 1990, began selling glass-in-glass jellyfish sculptures. The sculptures sold well. By 2002, P was designing and creating about three hundred jellyfish sculptures each month. P's sculptures are sold in galleries and gift shops in forty states, and they sell for hundreds or thousands of dollars, depending on size. P has registered several of his works with the Register of Copyrights. P's sculptures are 'vertically oriented, colorful, fanciful jellyfish with tendril-like tentacles and a rounded bell encased in an outer layer of rounded clear glass that is bulbous at the top and tapering toward the bottom to form roughly a bullet shape, with the jellyfish portion of the sculpture filling almost the entire volume of the outer, clear-glass shroud.' P's jellyfish appear lifelike. They resemble the Pelagia Colorata that live in the Pacific Ocean. During the 1990s, D, a glass artist from Hawaii, also began making glass-in-glass jellyfish sculptures. D's sculptures look like P's, and many people confuse them. D admits he saw a picture of P's jellyfish sculptures in American Craft magazine in 1996. And he admits he examined a P jellyfish sculpture that a customer brought him for repair in 1997. The glass-in-glass sculpture is a centuries-old art form that consists of a glass sculpture inside a second glass layer, commonly called the shroud. The artist creates an inner glass sculpture and then dips it into molten glass, encasing it in a solid outer glass shroud. The shroud is malleable before it cools, and the artist can manipulate it into any shape he or she desires. P sued D accusing him of copyright infringement. The district court granted a preliminary injunction, enjoining D from making sculptures that resemble P's. D appealed.