I used to go on concerts, closed events, inside/outside events and so on. There was often security frisking you to check if you wear booze or some dangerous items. Bottles are mostly no-go for such events.
I tried to find some good way, practical and invisible way to smuggle alcohol so I don't have to pay expensive but small amount of alcohol there.
Often security was checking my bag but when they saw only phone or wallet they let me go. So I realized that the bag is perfect way to smuggle alcohol but if only there was secret department in there.
I bought 3D printer and printed such bag. There were several problems: it leaked, printing took too long and I had to print in pieces and glue together. It was too much work for not so functional bag. I still think it is great and simple idea, but hard to accomplish. #diy source