not sure how to describe what i see on the front covers of my bronze age xmen 100. there is some color blotches where the color is faded. one book this anamoly is mostly on colossus thigh, storm hand and nightcrawler the other book its on xavier jacket, beast head, jean grey shoulder, cycops left arm and red text arrow above his head. not sure if this is from the printing machine where a book stacked on top wiped the color or was this from pressing. its smoothe to the touch. feels like the rest of the cover. my ultimate questions are what is this anomaly called, how was it created and how would this impact grading?