This is an occasional effect produced by the inner and outer cases being in direct contact with one another. The visual effect is similar to oil on a water puddle because of the two plastics.
Ultimately it is not anything that is in direct contact with your comic, nor will it affect the comic's condition over time. I SEE YOU SELL UNGRADED SIGNED BOOKS, DO THEY COME WITH A COA? All of my signatures were obtained by me at conventions/private sign ings or through a reputable 3rd party company (like Dynamic Forces). I stan d by authenticity of all the signatures I se l l.PLEASE CHECK O UT MY OTHER AUCTIONS. The item "Guardians of the Galaxy Annual #1 VARIANT CGC SS 9.8 signed Michael Rooker YONDU" is in sale since Monday, November 27, 2017. This item is in the category "Collectibles\Comics\Modern Age (1992-Now)\Superhero\Other Modern Age Superheroes".
The seller is "onestopcomic" and is located in Delray Beach, Florida. This item can be shipped worldwide.