Was just stealth vaping in the stall, or "vooping", as someone coined the term here on ECF recently, and was frantically waving my hand through the cloud before it rose above the partition to enrage the guy in the next seat ... Made me think how convenient it would be sometimes to have a juice that produces minimal vapor, or none at all, the ultimate in stealth vaping ... Most of the juices I've purchased so far have been the standard 80 PG/20 VG mix, and generate a modest plume ... I do enjoy the exhaled stream of vapor as much as anyone, for the satisfaction of a visual feedback response ... What happens with 100% PG ? Has anyone who does DIY found that the juice is undetectable without any VG ? Is there anything other than PG that could be used for nicotine delivery with no visible vapor at all, by intent ?