Copyright in art is limited to works that have no functional use. So, a drawing of a dress design is copyrightable but the dress design itself is not. The same is true for cars, shoes, coffee cups and jewelry. And chairs. And carports. Etc. This means that if you purchase a scarf knitting pattern, you can make as many of those scarves as you want. And even sell them (or try to sell them). But you can’t copy the pattern and sell it even if you make a few changes to the pattern.
On the other hand if part of the design is conceptually separable from the utilitarian aspect of the wearable article then that part of the wearable article is protected by copyright. So if that knitting pattern includes, say, an artistic expression of, say, a landscape or an abstraction of colors and stitches, that art is copyrighted to the artist who designed the scarf. Another example, in my necklace “Celadon,” the necklace conditions of a rope-like section, a pendent section, and a clasp section are not copyrightable. Neither are the bead weaving techniques. The actual artistry of the bead bezel, my unique color choices, and the bezel’s non-utilitarian ruffle make the work copyrightable.
The controversy stems from the blurring of lines between functional design and artistic design as we as a society begin to understand that art can be utilitarian, not only decorative.