Watercolor and Airport Security

Other artists have commented on difficulties of traveling with tube paints through airport security, and I had considered myself safe from that inconvenience, as I use pan paints, and watercolor sticks, when traveling. Actually, I have offered these alternatives as advice to others many times in the last few years. So it was very ironic and surprising to me that I got selected for further screening at Denver International Airport two weeks ago, and while my carry on was searched they explained they were after a stick that gave out a strange glow on their screen. The culprit? Daniel Smith Gamboge watercolor stick! After examining the stick they let me carry on with my trip. I had carried my watercolor sticks with me on board before, and even that very same color, without any problems. Indeed, I was on another business trip this week and again took my paints with me, same airport and same equipment, but this time there was no stop or comment about the gamboge stick... The life of the artist is never predictable, or boring...