I had my old, leather-covered briefcase swabbed several times in DEN and ALB. Once or twice they re-swabbed it without telling me that it tested positive or anything. Only had it swabbed once since 9/11 and the procedure was no differnt then before 9/11. It wasn't swabbed twice this last time around so I don't know if a positive would have caused a different, post-9/11 reaction.