The first time I stood in front of a moon jar, in a dim room in Seoul, I waited for the guide to explain what made it worth the trip. She did not. She turned the lights down further and told us to look at the seam. The jar had been thrown in two halves on a slow wheel, the upper bowl lifted and joined to the lower, and the potter had not bothered to hide where they met. I had come expecting perfection. I left thinking about the hand.
The seam is not a flaw that survived. It is the decision the whole form was built around.
Why the museum keeps the lights low
The charcoal ground you see these jars against in museums is not decoration. The kaolin glaze, fired above 1250 degrees in a reduction kiln with almost no iron, throws a faint pale celadon-blue only when the surrounding field is dark enough for the eye to give up on white. Stand the same jar on a gallery-white wall and it reads as cream. The curator's job, in effect, is to defeat the wall.