the idea of being able to hide your camp is cool and all but practicly speaking unless you are camping someplace your not supposed to it seems more a courtesy than a need, a courtesy I practice by the by. It could be that a reflective ridge line would be against this courtesy. But how about guy lines? you have to be relatively close to a camp site to see any guy lines with them so low to the ground. I camp where ever I can and often with others and quite often with others that are a bit tipsy. While I have never seen any injuries i have seen more than one wobbly wanderer face plant from invisible black guy lines. I have even stumbled and tripped a bit on lines when I Wasnt drinking, I havent fallen yet and I dont intend to, so I think visible guy lines are the way to go. Im allot more likely to fall over the guy lines than to have them seen by the enemy or the fuzz.