I think this is some much needed information around here. I knew some of this a few days ago, but after a heated argument on another forum I had to consult the professionals. This is what you should know about Nappa leather and coloring products for leather.
I'm happy to go over the information I gathered on leather care and the best products. I'll add to this post in a few days with that info, but be prepared, Leatherique leather care is not a favored product.
Alright here we go. I spent the past day emailing and calling a few professionals over in the UK that I had seen immaculate, OE type leather refinishing from. I've been cleared on many points, some were right, some were wrong. Hopefully everyone learns a little something from this. I may be using bits of knowledge that were already mentioned here, but this is meant to be a complete understanding.
Now, let's get a little basic background on how leather is made. The leather in question; BMW Nappa.
The leather is drum (VAT) dyed a matching color to the pigment color that is sprayed on later in the process. After the pigment, a clear coat matte (top coat) finish is sprayed on. The true dye process is not always done before color (pigment) coat and top coat are added. This depends on leather type and manufacturer.
What is leather dye and what is pigment?
-Dye is exactly what you would think a traditional dye would be. It stains, it colors, it soaks into the leather and changes the color throughout.
-Pigment is essentially paint. Modern leather pigment is a water based flexible "latex" acting type paint. If you sprayed it on smooth plastic (like a bag or acrylic panel) it wouldn't change the color of the plastic (like a dye would), it would leave a top painted finish. A pigment does not soak into the leather like a dye does. It "paints" on top of the leather attaching itself to the prepped finish.
What is the top coat?
Top coat is a protection coat to the color (pigment [paint]) coat. The finishes can vary from gloss, semi-gloss to matte. A top coat extends the durability, color, and life of the color coat by years and years (if proper care is taken). It also defines the total look and even feel of the leather. Top coats are also a paint, using the same technology as the color coat (polyurethane is one type).
Are there different pigment and top coat types?
Absolutely. Leather Clinic uses a water based Polyurethane type of formula. Leatherique uses a water based complex co-polymer formula. Each company will have their own formula.
When is a dye used?
Dyes are used (not always though) as part of the process leading to the color and top coat of modern leathers. It's also used in older methods of leather color as a stand alone method (ie; no color or top coat after).
How long does a color coat last alone?
The professionals say a color coat is only good for just a few years by itself at best.
How long does a color coat with a top coat last?
A color coat with a proper top coat can extend the life of the finish at least 3 times longer. A frequently used refinished leather would last 1-2 years with just color and at least 4-5 with a top coat added. The professionals say expect 5-7 years with a top coat and even longer if you're super careful and proper care products are used. Remember, a top coated leather is exactly how (nappa as an example) leather rolls out ready for upholstery. Some of us have 14 year old Nappa (like I do in my 96 M3) that is MINT.
What I was wrong about?
I had known Nappa leather was dyed and I have known that the leather had a top coat. I did not know that the leather had a color coat after dye. I also did not know what the color coat was... it's a paint, and "latex" in nature. The color coat is not a dye.
