Normally there are five different grades of leather and the details are as follows:
1)Full grain leather
2)Top grain leather
3)Split grain leather
Genuine and bonded leather aren't technically leather grades but the terms have been popularized within the leather industry, so we'll discuss them further to explain the complete leather grade spectrum.
All grades of leather undergo some form of treatment and tanning.
Before treatment and tanning, the hide is split, and this step is crucial to understanding how the different leather grades relate to each other.
The cowhide (also know as rawhide) ranges in thickness between 6 mm to 10 mm. Obviously, in the rawhide state, it not useable to make leather goods.
So the hide is split. The exact thickness of the split is determined by the customer's order and only takes the top cut into consideration.
The bottom cut has no bearing on the split.
If a customer's order was for full grain leather that was ~1.4 mm thick, the split would be greater than 1.4 mm, probably closer to 3 mm, as the top cut will be further processed and compressed to create the final end product.
The top cut is the most valuable cut and contains the full grain of the hide.
The bottom cut is the left overs and quite often is split further.
Its a piece of leather that has the full, complete grain of the hide intact.
All the rest of the leather grades do not have the full grain intact.
Full grain is the most durable and resistant to wear. In most cases, products made from full grain leather last a very long time and it will be the stitching that fails first.
There is a very wide range of leathers that fall under the 'top grain' umbrella.
The best way to really understand top grain leather is to compare it to full grain leather.
Full grain and top grain leather are both in the top tier of leather grades made from the top cut of the hide.
Split grain leather doesn't contain any of the hide's grain.
Probably the most common that most people have heard of is suede.
Its used to make the soft linings of other leather products, belts, wallets, handbags, jackets, purses
Genuine leather is the bottom of barrel of leather grades.
Well, technically there is still bonded leather at the very bottom, but genuine leather is definitely swimming very close to the bottom.
But it's also the real leather, not the artificial leather.