I have seen this on the reverse of a number of Walkers(and other types) as well and I suspect it is caused by long-term storage in a folder that had glue on the paper backing. Newer folders are typically glued on the cardboard and not the paper backing but if you look at an old folder(>40 years old) you will see the glue streaks on the paper backing.
Edited by biokemist6
04/24/2012 8:58 pm
04/24/2012 8:58 pm




















