I work in a suit and tie, low risk office environment . I often travel to government buildings and have to go thru the security screens. I evolved an EDC first aid kit, years ago. Not exactly a trauma kit, but its multi-use, light and cheap. Sometimes I carry two of them.
The "kit" is a well laundered, yellow or orange cotton bandanna . I HOT dry iron it and keep folding it to pocket size as I fold it and iron it flat. It's almost sterile, certainly it's aseptic. While its still HOT, I slip it into a sterile Gerber breast milk bag, press it flat with a book and seal the bag. I reinforce the edges with Gorilla Tape. Next I cut a bit of clear plastic report cover, 5"x2". I wrap four feet of Gorilla Tape onto the plastic. Then I tape the flat roll of tape to the bandanna packet.
The whole unit is ~5.25" x 3.5"x .25". It weighs next to nothing. I keep it in my front pocket with my wallet. Good security against pick pocketing. This unit is a bandage, chest seal, sling, tourniquet (with a pen barrel), smoke mask, signal flag and oh yes, handkerchief! Works for me and my whole family. Light and unobtrusive enough so that even the non prep oriented family members are willing to carry it, after a bit of nagging.
The above was posted on an Internet Forum. As a rule, when someone posts any sort of advice on a forum another person immediately needs to come by and claim that advice is not only wrong, but most likely deadly. The fact that nobody did so with the above idea, gives me hope that it's actually useful.
More proof that few things are more useful than a good 'ol bandana.
I'm tempted to try the above packing technique on a Triangular Bandage. It might make them even more compact than they come as packaged. And smaller is better.