Hey Guys...
Different materials for different jobs...
Obviously I really like synthetics such as Concealex, and use it nearly Exclusively .. I have a couple really nice knives that are in leather, anything else wouldn't do them justice..
However I find for the majority of my knives Concealex fits the bill.All of my knives are work knives, the knives I take into the field all get used, so any scratching they may get is more likely to be from use, then being drawn in and out of the sheath.
Trout Tamer,, not sure what you mean here :
"not be as subject to heat warping as plain kydex (sitting around a campfire, anyone?), and not hold in moisture next to the blade, due to the kydex... that's my ultimate sheath"
I haven't had a sheath yet that I've taken care of, warp due to heat. Sitting around the campfire should make no difference to a kydex sheath. You'll feel the heat on your leg far before the kydex will start to warp..
If you don't I suggest, you more your lawn chair back a few feet..
Also not sure what you mean by moisture in kydex ??
Each of the sheathing materials listed above have their place and time in the knife world. Not one will do each job 100% of the time. Each have their strengths and weaknesses, and all will fail at some point in time, or if pushed pasts it's optimal use. There is nothing yet to date that will fit the bill all of t6he time for every purpose.
The job the consumer has is to make an educated choice, or better yet, have multiple sheaths for different uses..Get some quality made stuff,, and I assure you,, you'll see and notice the difference in how each material works and has it's place, as an important part of your knife.
ttyle
Eric....
The leather/kydex sandwich is a great way to get the stiffness of kydex with the look of leather. 
Thanks for the info. Also, what I meant about kydex and moisture is that kydex won't soak up moisture as leather does, so in-sheath rusting is greatly reduced by the use of a kydex sheath.
