I've explained before, but i'll explain again.
Car leather is made from corrected grain leather. Basically after the beamhouse process (fat and hair removing) They use enzymes to remove fat's and proteins (thats what stops your leather rotting)
Then its tanned to give it the properties they want, softness etc etc. To do this they use a combination of PH and Temp to open the leather and they reinsert the fats etc that have been removed in beamhouse artifically. This is done in car leathers case by using chrome. The chrome gives the hide a blue appearance, and this is then sold as "wet blue" ,the cow hide is split into two parts, The bottom half goes away to be suede for the inside of shoes,low quality goods or artificial leather, the top section plus grain is kept for the higher end applications.
The tannery either makes themselves or buys in wet blue, and after that it is retanned to their exact specs. Again they use PH and Temp to insert the fat liquors etc they need for feel and softness. At this stage its also dyed, usually in a rough colour to what the final colour will be, so scratches don't show. Once this is done its usually corrected.
Corrected grain means on a number of occasions (unless you have very high quality cow hides, Bavarian as an example) The marked hide (brands insect bites barbed wire scrathes etc) is fillered, then buffed (big sanding machine to level the surface, A tannery makes its money on cutting yield, so the more pieces of a seat the car company can cut from one hide = profit. A big brand mark in the middle fcuks this up.
Once all thats done, Its finished, Acrylic resin and pigment as a base coat, Acrylic and PU as a colour coat, and then a PU Topcoat to protect, usually clear but sometimes pigmented.
Each of these coats has to have "intercoat adhesion" they basically need to stick to others so one doesn't peel off or crack. In this basecoat and colour coat process, it was also be printed, which gives the leather back its natural look, and prints on a fake skin look. The final topcoat is Crosslinked usually using a isocynate crosslinker, which hardens it up for scuff and abrasion resistance.
Now to heat and feed a pore as they say, minus any form of Ph influence. You have to go through 3 layers of dried resin, one of which is crosslinked , then magically open the pores, and drive this magic food through a shed load of chrome and fatliquors, which took the best part of a week to add correctly. All this can then "as it says on the bottle" be done in a matter of minutes".
Absolute COD s**t. LOL
Ond for the record, i spent a 3 months working at connelys before they closed, and even they admit they just make money on leather food because " if they are silly enough to buy it we'll sell it"