Section through automobile leather upholstery
Prior to 1980 most automotive leather upholstery used was high-quality top grain full grain leather with a pigmented solvent-based Nitrocellulose lacquer coating and their unstable plasticizers would easily migrate in the heat from sun exposure and again create 'fogging' on the internal surfaces of the windows. As a result of this plasticizer migration the use of oil-based products that contained solvents to keep them from becoming brittle and cracking, creams, waxes and oils were needed in aftercare products to try and bring the suppleness back into the leather
By applying an oil-based conditioner and allowing time for it to work in a heated environment. By covering the seats with a plastic bag to help retain the heat and then leave overnight will ensure the oils permeate the lacquer and reach the leather hide. This process can also be used for equestrian tack; bridles, harnesses’, saddle and leather chaps and riding boots
Automotive leather and finished leather surfaces have undergone major technological improvements over the past few decades. The leather used for automotive upholstery is finished leather; the ‘finish’ applied to the leather hide is a pigmented (colour) urethane protective layer and a clear abrasion resistant topcoat.
Unfinished vs. Finished leather
a) Unfinished leather - the appeal of this type of leather is its initial "natural" look and the soft, supple texture. The downside is aesthetic vulnerability; due to the porous nature of untreated leather, it stains easily and it is sensitive to ultra violet (UV) light, which means that the colour is subject to photochemical degradation (bleaching, (fading), discoloration, chalking, brittleness and cracking) all indications of UV deterioration. The porous nature of unfinished leather will allow a water- or oil-based solution to permeate the leather.
b) Finished or micro pigmented leather - is commonly used for the automobile as these resins create a film that protects the leather. This 150µ (micron) protective covering comprises a multi stratum acrylic and polyurethane resin binder system covering over the leather hide; the top strata are the surface pigmentation (colour) and an abrasion resistant urethane is used to improve flexibility, fastness and adhesion to the leather, together with a clear top coat provides a very durable surface finish
The water-based urethane pigmented (colour) coat and the clear topcoat provides abrasion and stain resistance. This type of leather finish is the most durable and easiest to care for but tends to be stiffer than both unfinished and micro pigmented leather. When Ford first introduced its King Ranch leather in their F-Series trucks it had unfinished leather, later they adopted a micro pigment type finish
Using advanced micro pigments this finishing technique makes the finish rigorous enough to stand up to the conditions it would be subjected to in an automobile. Generally speaking, micro pigment style leathers come in very earthy natural colours, incorporating a small quantity of pigment (a thin clear sealant that provides a uniform colour and affords some protection) but not so much as to conceal the natural characteristics of the hide so it will still retain the soft hand of Aniline leather. This type of leather is also used for perforated leather finishes.
Top-grain premium Aniline leather is mostly used in prestige European automobiles; Aston Martin, Bentley, Ferrari, Jaguar, Lotus, and Rolls Royce, US Cadillac and high-end German automobiles such as; Audi, BMW, Daimler AG, Mercedes-Benz, and Porsche.
For some of these vehicles premium leather is standard OEM specified equipment, but for most, it’s a ‘premium’ package that costs upwards of 2,000 USD. This is the niche market sector both Leatherique and Connolly were originally formulated for.
Be cognizant that most if not all OEM leather in these vehicles is now a semi-aniline (micro pigmented) finished leather Is a term used by the auto leather industry to better describe leather with a thin urethane layer of pigment coating, which provides an even colour and both abrasion and stain resistance. As opposed to the mislabelled Aniline leather (aniline is a dye (immersion) method, not a leather type), which will absorb body oils and moisture and would be subject to abrasion unless it has been treated in some way.
I hope you’ve found this article both informative and helpful.
TOGWT® Autopia Detailing Wiki Articles
1. “Leather Upholstery Type Surface Identification”
2. “Leather Articles Hyperlinks”