Here are close-ups of some of the leather grains available. We use all these on our Bible rebindings. Some of our leathers have a natural grain and others have an impressed grain. Some come in a variety of pre-dyed colors, while others can be hand-rubbed to achieve a desired color. Some are more flexible than others.
The versatile stand-by -- pigskins:
The above are close-up examples of two of the more popular pigskin grains., mission grain and natural grain/
"Retro"-grain deerskin, natural wild-grain goatskin, and wave-grain calfskin.
Here is a close-up of the impressed Imperial design sheepskin with the "bomber jacket" lambskin.