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bigcam09
06-17-2021, 07:42 AM
Dear Roger,

Two years ago I purchased a 2017 Audi A4 from a dealer and didn't realize that there was a stain on the rear center leather seat until many months later. I think the dealer cleaned it but eventually whatever they did wore off and the seats have looked like they do in the pictures below ever since. I do not know what caused the stain so I'm unsure how to go about removing it (if possible). Do you have any suggestions?

Thank you!

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Roger Koh
06-19-2021, 04:16 PM
>>> I do not know what caused the stain so I'm unsure how to go about removing it (if possible). Do you have any suggestions?

Leather Stain Identification

Appearance - Stain identification by appearance will show whether it is the characteristic of a spill, rub-on, penetrated, or deposited. It may also reveal dye or finishes damages caused by the stain.

Odor - Stain identification by smell can be very helpful in positive identification. Some of the more common odors may be moldy, smoke, putrid, or ammonia from urine.

Color - Stain identification by color will also give a clue to the staining material. If the stain is red, it could be beverages, nail polish, lipstick, blood, or some other things. Color identification may not necessarily be right; with time, a red bloodstain may turn to a stain that is tan to black. The color of the leather may mesmerize or alter the color of the stain.

Feel of Hand - Stain identification by feel of hand may help determine the stain types. For instance, if it is sticky and red it could be candy, beverages, or other things that have sugar in them. If the stain is brittle and stiff, it may be nail polish, shellac, or paint. If it smears, it may have a grease base to it, such as lipstick.

Location - Stain identification by location may give a clue as to the makeup of the staining substance. If it is dark at the headrest or the edge of the armrest, it is most likely stain by body oil, grease, and perspiration by hand or by the head.

Buildup or Absorbed - A stain may take several appearances. The stain may be lying on top of the leather (buildup) on most pigmented leather or absorbed into the leather on most unfinished, aniline, and nubuck leathers. Naturally, it could also be a combination of absorbed and built up. If it has been absorbed, this will be an indication that it was a liquid when it penetrates the leather. It should also alert us that it may have chemically changed the dye of the leather. An example of this would be a perspiration stain that has reacted with the leather dye and changed it in some way. This would occur more likely on dyed absorbent leathers. The perspiration could also have weakened the fibers of the leather. In any event, this leather may show a marked color change in that area after spotting, and possibly after cleaning. Examples of built-up stains are paint and some foodstuff, etc. Examples of absorbed stains are beverages, wine, tea, coffee, etc. A combination stain may be lipstick, ink, mustard, etc. it will have part of its staining matter absorbed into the leather and part of it accumulated on the surface. A stain may also be a substance that has wet solvent-soluble and dry solvent-soluble components combined. An example of this would be gravy which contains grease, flour (from plants), and milk (from an animal). Paint-type stains are readily detected because of their stiff nature and generally bright colors and they seem to be sitting on top of the leather. When identifying stains, always try to determine whether they are of a protein, cellulose, oil-based, or colloidal make-up nature. Three common types of soiling or stain are solvent-soluble, water-soluble, and insoluble. Stains are frequently of a combination nature, and in most instances, there will be no information from the customer regarding the stain especially if they are bought used.


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Roger Koh
Leather, Skin, Hair, Eye & Acne Care System Formulator
Consultant / Practitioner / Instructor / Coach
web: www.leatherdoctor.com
forum: www.leathercleaningrestorationforum.com
email: [email protected]

Roger Koh
06-19-2021, 04:19 PM
Here's a leather problem solving matrix for auto seats.

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Roger Koh
06-19-2021, 04:20 PM
Here is the link for auto pigmented care Kit-Ap3 for your further readings.

https://www.leatherdoctor.com/leather-auto-pigmented-care-kit-ap3/
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