These anomalies are not on the book itself, and are just an effect of the cases inner well pressing against the outer capsule. The Newtons Rings can occur in varying degrees from barely noticeable to significantly visible. There is unfortunately very little to be done in terms of re-holdering books which exhibit these rings, as there is no guarantee from the company responsible that the effect will not occur on the re-holdered book to the same degree or more.
If this effect is bothersome to you as a collector, we strongly suggest sending a note to the company responsible for encapsulating the books and urging them to rework their holdering processes to cease the occurrence of this effect. The item "Jungle Action #6 (CGC 8.5) O/W pages 1st Black Panther solo story (c#21912)" is in sale since Monday, February 11, 2019. This item is in the category "Collectibles\Comics\Bronze Age (1970-83)\Superhero\Other Bronze Age Superheroes".The seller is "gdcomics" and is located in Easthampton, Massachusetts. This item can be shipped worldwide.