Information on the internet regarding the care of leather is scarce, often contradictory, misleading, or simply wrong. Mis-information can lead to inadvertent damage to your leather articles. Our goal is to present clear, concise, accurate information. Before you can learn how to care for your leather, you should know the type of leather you have.
First, here is some base-line information about leather to help you better understand its properties.
Leather is a natural product. It comes from animal skins which have been chemically processed (tanned) to preserve them. A properly tanned hide (or skin) creates strong, flexible material, resistant to decay.
Most leather is tanned cow hide. Cow hides are about 1/4 to 3/8 inches thick, which is too heavy for general upholstery application. Therefore, hides are split laterally, rendering an upper and lower cut.
The upper portion is the "top-grain", or "full-grain". The lower portion is the "split". This cutting process creates different “faces?to the leather. The outside face of the top- or full-grain shows the natural grain characteristics, but is otherwise smooth, whereas, the underside appears as suede".
Now let’s determine what type of leather you have. There are two basic categories: "Finished" or "Unfinished". Briefly, finished leather is dyed, and then coated with a pigment-based leather colorant. Unfinished leather is dyed only. Finished leather is protected, unfinished is raw.
The following table depicts comparative features.
|Color -||Pigmented color coating on the leather's surface.||Aniline dye color in the leather.|
|Stain Protection -||Color coating protects against staining.||Absorbs liquid and is prone to staining.|
|Fading -||Pigment coating is fade resistant.||Dyes fade from light exposure. (UV)|
|Color Richness -||Color coating is uniform, lacking depth, except when certain coloring techniques are used. These usually involve the application of a uniform base color, and then a darker, non-uniform print is applied over the base color, providing a more organic color rendering due to the contrast between the two.||Coloring is naturally non-uniform due to the varied porosity of the hide itself. The dye saturates the hide at different levels, creating color variations that accentuate the natural beauty of the leather.|
|Feel (or Hand) -||Leather feels harder, colder, stiffer||Buttery soft, warms quickly, inviting|
So, simply put, finished leather color is from a pigment coating on the leather, whereas unfinished is from a dye in the leather. Finished leather is stain and fade resistant but lacks deep richness in color, and tends to be stiffer. Unfinished leather is soft and natural-looking but fades and stains readily. Unfinished leather tends to be more expensive. This graphic depicts the difference between finished and unfinished.
Note that the topical coating can range from thin to thick. If there is a very light color or clear coat on top of aniline-dyed leather, it is often referred to as “semi-aniline.? Semi-aniline leather offers modest protection while retaining much of the aesthetic beauty of an unfinished aniline-dyed leather.
If you're still not sure, or want to learn more then see below for more detailed descriptions of finished and unfinished leathers.
"Finished" : The leather has a topical pigment coat applied. One of the most common coatings consists of a soft acrylic color coating under a urethane clear coating (for durability). These resins create a film that bonds to the surface of the leather. It's primary goal is to protect the leather, providing wear, stain, and fade resistance.
Finished leather will resist staining by water- or oil-based agents (if a drop of water is put directly on the leather surface, the water bead remains on the surface, and does not soak in and darken the material.) The clear coating mentioned above determines the final reflective value of the leather surface (ranging from high gloss, all the way down to a matte or dull finish, depending how much dulling agent is added to the clear coat resin before application), so sheen is not necessarily a help in determining leather type. Generally, finished leathers do not have that "buttery soft" leather feel (or hand) associated with raw leather. Also note, finished leathers can be described as aniline-dyed, and still have a topical pigment applied. Finished leathers are much less susceptible to fading.
"Unfinished" : The leather does not have a topical pigment applied, or has a minimal resin coating to retain the hand of raw leather. The color is achieved by immersing hides in aniline dyes that are absorbed into the leather, accentuating the natural beauty of the hide. Because leather's absorption characteristics are not uniform, variations in color are common. The water drop test will result in the drop transferring into the leather, darkening or staining the area. Because unfinished leathers are colored using organic aniline dyes, they are much more susceptible to fading (caused by UV exposure).