Leather is graded by the size, location and extent of the natural blemishes like wrinkles and scars that are inherent in all natural hides.
These hides are separated into layers. The top layer is known as the top grain. If you were to examine the top layer under a microscope, you would see fibers running in all directions, making the top grain layer of the hide very strong.Whereas Full Grain leather is made of layers 2 and 3, Top Grain leather is the upper 2 "skin” layer, with the lower 3 “split” removed. It’s thinner without the split and also more pliable, but still 100% high quality leather. Top Grain leather is very commonly used in higher-end furniture production, because it’s still durable like Full Grain leather, but more affordable because less-perfect hides are used, so Top Grain leather is produced at a higher volume.
Since hides used for Top Grain leather have more blemishes and irregularities than Full Grain, part of the production process includes sanding the surface of those flaws away, and then stamping a faux grain back onto the leather, so that the final piece appears flawless.
There’s a vast range of quality and price within top grain leathers, and what’s best for one may not be best for others. Part of leather furniture’s great appeal is luxurious comfort. The finest of top grain leathers will have the softest feel, but may not be as desirable if ease of care is important to you. They tend to be a little more temperamental.
Finally, no matter how well it is cared for, all upholstered furniture will fade with time and exposure to light and heat so it's important to keep that in mind.