yes some patterns do but usually not that close in thicknesses. some liners aren't even leather. he needs a definite idea of the pattern he intends to make first off.
make stuff that uses the same thickness leather. you can do that easily enough with wallets, tags and such. you specd variations of less than one mm. pick the mid thickness and go with it.
I'll drink to that lol. It is getting close to brewing season here. we will be picking chokecherries today then later in the week we will be going out for Service berries. They will be wine for the next winter or two. Apples and such go to Brandy.
cardboard has been used for years as liner for manufactured leather work, right or wrong. I wouldn't think a bag in that price range would have it in it however.
my only guess is that if they used thicker leather they would have to use two thicknesses which would increase cost in their product instead they use one thickness and add layers of crap. Matching color is also a possible reason.
the inmates where i worked used to melt down styro-foam cups and make shivs/shanks. yes they only need to work once. you would be surprised how sharp they can get. their easiest one was just melting a razor blade into a tooth brush handle Yours is much more refined lol.