From watching Forensic Files I know that CA fumes can adhere to and highlight fingerprints. I clean my glue looper by burning off the dried CA, and I think that may be what happened here. The MR Hobby Premium clear coat is well dried and most fingerprints just wipe off…but not this one. I also clean the un-used CA out of my little glue well with a Q-tip and that instantly makes lots of fumes for some reason. And I am careful not to breath the fumes when doing this.