Is there is any explanation for why Rorschach's iconic black-and-white mask in Watchmen (and likewise the dress that the mask was originally made from) is symmetric about the center line?
The out-of-universe reason is that when Alan Moore was first developing Watchmen, he was originally going to be using the Charlton Comics characters that D.C. had recently purchased, and Rorschach's role in the story was originally going to be filled by The Question.
The Question was an obsessive crime fighter who wore a blank mask to hide his identity. The facelessness (whether Rorschach's or The Question's) is a key feature of the character, so Moore had to design a new similarly masked character when D.C. decided that they did not want him to use the heroes from the Charlton Comics stable. He hit up on the idea of a character with the Rorschach inkblot test theme — with its black-and-white imagery and suggestions of mental problems.
The Rorschach inkblots were originally created by blotting India ink between the folded pieces of card. Thus, they were bilaterally symmetric.
However, the explanation in the comic for how the dress material was created does not seem to suggest any reason why the pattern should have an axis of symmetry. Was this addressed somewhere in the original Watchmen series/graphic novel, and I just missed it? And if not, has it been dealt with in any other works set in the Watchmen universe?