Imperfections are aspects to the piece, contrary to what I was trying to achieve.
If I have a piece, where I wanted clean lines, or definition between colors and I have drips or smears, those are imperfections. If I have a piece that I want to be as symmetrical and even as possible, that is a bit oblong or uneven, that is an imperfection.
However, if I am layering glazes with the purpose that they run and mix in an interesting way, I won't mind some random/ unexpected drips. If I have a piece, that I ad a groove or swirl, which causes some distortion, I obviously won't care if it a bit off elsewhere.
And I've actually had the opposite problems. I've had glazes I wanted to run in an unexpected way, that stayed put. I've had forms that I wanted to be a bit skewed, that were a bit too perfect. In that case, the perfection was the imperfection.
So I guess it's all about my intent.