Any level? CGC slabs have had Newton rings in one form or another since CGC opened 16 years ago. Where ya been?
That level should be clearly defined so as to be consistent and should also be written in to policy and stated as part of the grading process / QA step. If it is I missed it but if not (could someone please point me to where it is written?) it makes sense. I understand Newton Rings have been around for some time, years and years in fact, but many people do not know this and are taken aback when they appear.
Disclosing this potential and setting the expectation will only help. Also, where is the line drawn between acceptable and unacceptable?
I'm glad you found that amusing