I made a leather one and am quite happy with it .....
It is double walled with suede on the inside, regular leather outside ,
and has more leather from a belt in-between chisels that is stitched through to not get cut .bits shoved in the ends too.
Very happy/surprised with it
(this is out in the open)
Most other stuff out of leather seems to work too, but these are just bedding at this stage ....
Intended to be customised to particular tools, at first (waste of time doing that for the most part) ...even with extra spaces.
I like the chisel roll and the scraper wallet though ..maybe the saw (wallets?) is just ok
The suede interior seems to be a good idea (my suede)
Most of my leather goods with tools inside sits in sturdy plastic boxes that can stack up making them airtight.
Then there in old beer fridges too...not airtight but kinda
In contrast I made a few quirky plane holsters from leather boots and some are just awful ....
Whatever acid or whatever they do . the leather is corrosive no matter how much oil i POUR into them ..
The leather just drinks it up ...and it still reacts with the bronze too making a copper blue colour excrete .
Bottom line is if your scavenging leather from charity shops ...you don't know what your getting.
And you got's to know your leather ...some is very convincing laminates etc...
Some of these I've found to be corrosive and your thread can rip through them.
You haven't mentioned why you want to protect your tools i.e
Do you plan on leaving them alone for periods of time .
I've found a lot of my tools are better off in the open.
Maybe its a better idea to have them in an unheated place, where the air is the same temperature as the tools.
If warm air hits cold tools it will condense on them and rust ..warm air holds moisture .
Or have a heated tool cabinet where any heat escapes outside to the colder room .
If I had to store tools for a long time I think plastic wrapping would probably be a better solution ...
Provided they don't rip ...
Or fitted boxes which have camphor in them evaporating and always leaving a oil film on tools .
Interested to hear others perspectives