that one little defect that moves something from attractive to beautiful. The imperfection that brings "perfection". The thing that, if fixed would remove character.

Years ago there were automated calligraphy systems that were a dismal failure--they were technically accurate. Competent but uninspired. Somone added noise to it, and they were a big hit.

Referenced in the piano tuning episode of Northern Exposure

Cliche theme of much 80's sci-fi, where mankind defeats the evil perfect robot army through creativity. I think Star Trek (obcviously not 80's) also went there. Maybe it was novel then, but I doubt it.

In some religious community, perhaps the Shakers, it was believed that only God could create something perfect. Hence creating a perfect object was considered trespassing in God's domain. So all crafts, from chairmaking to quilting to painting, had to include a perfect flaw. Of course, some flaws rendered the object unusable. So a secondary art form emerged, of creating a beautiful "flaw" inconsistent with the overall work, yet appealing in its own right.

example: The sweater I knit with one cable twisting in the opposite direction from the other cables.