In Chinese and Japanese brush painting a small error is generally found especially in the older masterpieces.

Yes, I came across this in a short story a while back (which is unrelated otherwise to what I am looking for) where the old chinese master left a very great work of his with everything but one eye of the dragon complete. Then the student had the gall to get up the ladder and paint it in. The dragon sprang to life, and killed the student, (possibly others in the way too) and flew off.

Poking at my memory makes me feel that the quote I am looking for did refer to relgious texts as the example, but refered to all writings. And just books. Not rugs or anything else (though very interesting to read up on. Thanks!).

Ali