I think there must be different levels of GM's, just like the straight fakes, you got those horrible 30 dollar fakes all the way up to the super perfects or whatever they call them. It might be the same thing with GM's. Maybe some are made with the same materials in the same factory. And some are made in the same factory with leftover materials,but if they run out of certin materials they just replace it with something close to that material. I think there's a combination of things going on here. If a GM shoes was exactly the same as authentic no would know and no one would be able to tell the difference, so they'd never be called GM. It's the GM's with the small differences that let people know that GM's actually exist.
I'm not saying any of this is fact, just speculation on my part.
This is exactly the case. I have a reasonable amount of knowledge about this kind of thing due to my experience Toy Manufacturing Industry. There are many different levels of "Fakes"... Ill try to break this down simply using sneakers as examples.
Knockoffs - Product made to resemble a known property, but does not use trademarked logos and has enough differences as to not infringe any copyright law. ie: Walmart/Payless 4 stripe "Adidas"
Bootlegs - Lowest level counterfeits. Cheaply made, obviously fake products. May or may not use trademarked logos. ie: Spongebob Jordans, 360 Air-Max soled Jordans, etc.
Fakes - Cheaply made, inexpensive counterfeit products that infringe companies trademarked logos. Products are usually severely lacking in quality. Fakes are most commonly reverse engineered from an authentic. This is why the old Hata-Takahashi fake XIs from the early 00s resembled the OG 1996 shape instead of the 2000/2001 lasts and why outright fakes differ so blatantly from the authentic product. Early HT fakes even had slightly "worn down" soles when they were brand new, because the XIs they were reverse engineered from were not DS. ie: Superbs Jams a few pages back
Grey Market - Unauthorized products produced with the copyright holders blueprints and specifications of the authentic. When a company hires a contractor to manufacture a product, that contractor now has the means to reproduce that product on their own. Many (almost all) contractors do this and while the product is not necessarily made in the same factories or with the exact same construction methods, they are
extremely close to the authentic product. Because contractors have access to the materials for production, Grey Markets typically made with the exact same materials used on the authentic. ie: most of the shoes ITT
Third Shift/Backdoor - Unauthorized products that are identical to the authentic. These use the same construction methods and are made in the same factories, by the same workers as the authentics. This happens when contractors intentionally overproduce a product with the intent of selling the extra stock themselves.
Defective/B-Grade - Authentic products that are deemed flawed by the manufacturer and sold to discount stores or sent to factory outlets. ie: Shoes stamped with the "B" on the tag you might find at the Nike Outlet or Marshalls (I haven't seen any stamped B-grades in a long time, most of what the outlets sell is leftover dead stock)
Authentic - Authorized products sold through official channels. ie: the stuff you buy from NDC, FL, etc.
aksuited
and would also like to know, and Zyzz if you hear or find out, can you let me know mate. 
.. 
