The first thing to keep in mind is that leather is a natural product. Each hide is just as unique as your fingerprints. The color, texture, and markings vary from hide to hide and even within a single hide. It is not unusual to see color differences, grain changes, and even scars or brand marks on a piece of furniture. Different types of leather display these characteristics in varying amounts, and it's up to you to determine what exactly you want from your leather furniture.
ANILINE
Aniline leather is a type of leather dyed exclusively with soluble dyes. The dye colors the leather without producing the uniform surface of a topcoat paint or insoluble pigmented sealant. The resulting product retains the hide's natural surface.
Choose this leather if: you love the soft feel of leather and truly appreciate the beauty of each hide's unique natural markings, but expect only light to moderate use of the furniture.
SEMI-ANILINE
This type is fairly natural. The hides are first aniline-dyed and then coated with a slightly protective topcoat that may or may not contain some additional color. You will see some natural markings through the topcoat and it can still stain or fade somewhat, but it is more protected than a pure aniline leather and the color is more uniform.
Choose this leather if: you appreciate the softness and texture of leather but also expect to use your furniture regularly.
PIGMENTED/PROTECTED
This type is the least natural. Still Top Grain leather and dyed all the way through the hide, but the surface is coated with a heavy protective topcoat that has color added. Pigmented leather is usually buffed (sanded) to remove imperfections in the hide and then embossed with an artificial grain. The color and texture tend to be flatter, without the deep rich color or luxurious feel of Aniline... but it is also the most durable and cleanable leather type.
Choose this leather if: you anticipate heavy use of your furniture, so you don't mind sacrificing softness and texture for higher durability.
NUBUCK
This is top grain leather that has been buffed (sanded) to soften the surface and give it a "suede-like" appearance. It is extremely soft and very luxurious, and also stronger than suede which is made from split hide. Like other anilines, nubuck leather is very susceptible to fading and soiling, and will develop an aged patina over time.
Choose this leather if: you want to make a bold fashion statement with a luxurious and truly unique piece, and don't mind some maintenance and care.
Leather information from www.smithbrothers.com