Leather Fatliquor 5.0

 Leather Fatliquor 5.0 by Leather Doctor is a pH 5.0 micro-emulsion of fat, oil, and water to restore the leather's original softness, strength, and flexibility.

 How It Works:

 Replenishes Essential Fats & Oils 

• Prevents leather from drying, stiffening, or cracking

 Enhances Leather’s Suppleness & Elasticity 

• Maintains a soft, luxurious feel

 Strengthens Leather Fibers

•  Improves tensile strength and durability

 Creates a Breathable Structure 

• Ensures leather remains pliable without feeling greasy

 Prevents Brittleness & Fiber Breakage

•  Essential for long-term leather preservation

 Application Process:

When applied, the water-encased fat and oil molecules penetrate deep into the leather fibers. As the water gradually evaporates, the fat and oil molecules hydrogen bond with the fibers, creating a breathable, flexible structure that enhances leather’s resilience and longevity.

 Ideal for Restoring & Maintaining:

 Vachetta Leather
 Aniline Leather
 Nubuck
 Suede
 Shearling 
 Woolskin
 Full-Grain Leather
 Vegetable-Tanned Leather 

 Proper fatliquoring ensures that leather retains its tensile strength, resists breakage, and maintains its natural softness, preventing premature aging and deterioration.

 Fatliquor

Fatliquor plays a crucial role in the leather’s conditioning process by replenishing the fat and oil content that keeps leather supple and prevents stiffness or cracking. When applied, the water-encased fat and oil molecules penetrate the leather fibers. As the water gradually wicks away during the drying process, the fat and oil remain, hydrogen bond with the fibers and creating a breathable structure that enhances the leather’s elasticity and durability. Fatliquor 5.0 is essential for maintaining and restoring vachetta, aniline, nubuck, suede, and other leathers, preventing them from becoming brittle over time. Proper fatliquoring ensures that leather retains its tensile strength, resists breakage, and continues to feel soft and luxurious.

 Fatliquor Principle.

Almost all leathers including nubuck, suede, hair-on, sheepskin, and shearling finished goods will need periodic conditioning to replenish their diminishing fat and oil content to regain their softness and flexibility. This is attained in the fatliquoring process by introducing fat and oil into the leather so that the fibers individually are uniformly coated. The percentage of fat liquor on the weight of leather is quite small 7-14%. The technique of distributing this small amount of fat and oil throughout the leather will affect its subsequent useful life. It is necessary to emulsify the fat and oil to allow a small amount to be spread uniformly over a large surface of the leather fibers. In an emulsion with water, the fat and oil are dispersed in microscopically small droplets, giving it a white, milky appearance, just like milk is an example of a natural emulsion. The fat and oil droplets must remain as a milky emulsion until they penetrate the leather, not separate as large drops or as a layer of oil, which could not penetrate the leather fiber and would only give a greasy surface layer. Fatliquor, the lifeblood of leather makes important improvements to its properties; they play a fundamental role in governing the softness, pliability, stretch, or hand; the ability to resist water; the resistance to abrasion, and the smoothness of the grain. The effect obtained will depend upon the type of leather; the quantity of fat and oil; how it is applied and whether it is all on the surface or has penetrated the internal structure.

 Fatliquoring Chrome-Tanned vs Vegetable-Tanned Leathers.

If the fiber structure is tightly woven smooth or finished, the leather will be firmer, making it more difficult for the fat liquor to penetrate the fibers uniformly. Chrome-tanned leather with diminishing fat liquor dries out firm, stiff, and hard. However, spreading a relatively small amount of fat liquor over the fibers, readily reduces the hardness, improving the stiffness for its softness and stretchability. Vegetable-tanned leather with diminishing fat liquor is less hard than chrome leather; however, more fat liquor must be added to vegetable-tanned leather rather than chrome leather to obtain the same softness or stretchability. Normally the leather becomes softer and stretchier as more fat liquor is used however, excessive amounts of fat and oil may give an undesirable, greasy feel, or may interfere with redyeing and refinishing.

 Fatliquor Softening and Lubricating Properties.

Fatliquor promotes the lubricating of adjacent fibers rubbing against each other or reduces the adhesion between them. Fatliquor is applied to the wet leather to prevent the fibrils from sticking together during drying. Fatliquor gross penetration into the inter-fiber spaces the fat and oil molecules are hydrogen bond to the molecular leather fibrils. Fatliquor is ionic negative (-ve) charged which gives a much firmer attachment to the ionic positive (+ve) charged leather fibril, with less migration during drying, thus less fiber collapse during drying, and hence a fuller leather.

 The Effects of Fatliquor on Leather Drying.

Fatliquor is applied to the damp leather, ideally when the leather fibers are fully hydrated but little free water exists in the spaces between the fibers.   Fatliquoring to completely dried leather fibers results in rapid absorption, often resulting in dark-colored, greasy patches, moreover, the resultant leather is not so soft, resilient, or full as when fat liquor is applied to the damp, hydrated fiber. This is because without or insufficient fat liquor and when leather dries, the fibers shrink due to loss of water and come closer together, when cohesive forces come into play, cross-linking the fibril or fiber structure, making it firmer, harder, and less flexible or "crusty".  These forces may be of the nature of Van der Waals forces or dipole or hydrogen bond forces, which would be much stronger. The degree of crustiness will depend upon the tanning type, being less with vegetable tanning, which may account for many of the hide's dipole forces, and more with the chrome tannages, where the effect is less.

Fatliquor 5.0 Plus is the leather scent version.

Instruction:

1. Concentrate is mixed well before adding distilled water 1: 5 before use.
2. Apply and redistribute with appropriate brushes or pads until structure is saturated.
3. Repeat each cycle water contents evaporate leaving behind only the fat and oil content.
4. Allow natural drying for extra softness.
5. The desired suppleness is further staked and massaged, accordingly with a little wet back with Hydrator 3.3 until dry.

 People Also Ask:

1. What is Fatliquor?
2. How does Fatliquor Work?
3. Why Does Fatliquor Work?
4. When Does Fatliquor Work?
5. What is the Purpose of Using Fatliquor?
6. What is the Purpose of Fatliquor?
7. What is the Original Percentage of Fatliquor Content from the Tannery?
8. How does the Fatliquor Content of Fat and Oil Diminish?
9. How to Determine the Percentage of Fatliquor Required by the Leather?
10. How to Calculate the Percentage of Fatliquor Required?
11. Why Hydrator 3.3 Before Fatliquor 5.0?
12. What is the Ratio Usage between Hydrator 3.3 and Fatliquor 5.0?
13. Product Reviews - Posted by Larry Bauman on 31st Jul 2017 -The Lazarus Effect 

 What is Fatliquor?

1. Fatliquor 5.0 is a pH5.0 micro-emulsion of fat, oil, and water for rejuvenating, restoring, and softening all leather and suede types imparting their original suppleness and conditioning them from dry rotting and stiffness. 
2. Concentrate when mixed with 1: 5 parts of distilled water turns into a milky micro-emulsion similar to fresh milk ready to use.
3. Stiff or dried leather and suede are hydrated and relaxed with Hydrator 3.3 before an effective fat liquoring.

  How does Fatliquor Work?

1. Fatliquor 5.0 typically works after hydration with Hydrator 3.3 to open up the fibrous leather structure, ensuring thorough and even absorption of fat and oil. 
2. The fat plumps the leather with fullness and the oil lubricates each fibril like millions of interconnecting hinges to glide over one another smoothly once the water content evaporates.
3. Effective fat liquoring after hydrating produces a softer leather with increased tensile tear strength.

  Why Does Fatliquor Work?

1. The fat content in Fatliquor 5.0 plumps up the leather, preventing it from easily collapsing into creases and wrinkles during stress or flex.
2. The oil content lubricates the fibers, allowing them to slide over one another smoothly like millions of interconnecting hinges.
3. Fatliquor 5.0 helps to keep leather at its optimum physical performance and prevent premature aging.
4. Fatliquor 5.0 softens the leather when dry, providing stretchability, compressibility, and flexibility while significantly increasing its rip tensile strength.

  When Does Fatliquor Work?

1. When Fatliquor 5.0 is applied, the water-encased molecule breaks free when an ionic attraction occurs between the fat and oil with the leather fiber.
2. The excess free water content is wicked out, leaving the pores breathing space for the natural transpiration of the leather.

  What is the Purpose of Using Fatliquor?

1. Fatliquor 5.0 carries an ionic negative (-ve) charge to hydrogen bond with the ionic positive (+ve) charge leather fibers, thus freeing up pores for better breathability.
2. Unlike other stuffing conditioning oils and waxes that fill up the breathing pores suffocating the breathability.

  What is the Purpose of Fatliquor?

1. Fatliquor 5.0 conditioning replenishes the original fat and oil that diminishes through sun bleaching, aging, heat, and alkaline over-exposure or cleaning.

  What is the Original Percentage of Fatliquor Content from the Tannery?

1. Fatliquor content retained after a universal tannery when dries varies by an average of up to 14% depending on the leather type and its usage.

  How does the Fatliquor Content of Fat and Oil Diminish?

1. Fatliquor percentage drops as the fat and oil content diminishes through aging and heat, or when it is leached out by water or chemical overexposure during cleaning.

  How to Determine the Percentage of Fatliquor Required by the Leather?

1. The fatliquor content required by the leather is based on the weight of the leather to the percentage of remaining fatliquor.

  How to Calculate the Percentage of Fatliquor Required?

1. Fatliquor requirement is simply calculated by the weight difference in percentage.
2. If the weight of the leather is 100gm and the leather moisture reading is less than 1%.
3. Applying 80gm of Fatliquor 5.0 will deliver an incremental of 13.3% fatliquor when dry as the 66.6% water content evaporates.

  Why Hydrator 3.3 Before Fatliquor 5.0?

1. Hydrator 3.3 is used as a hydrator to relax, open up the inter-fibrillary spaces, and facilitate and redistribute colloidal water movement.
2. Besides, protonating is used to post-clean fatliquor surface remnants.

  What is the Ratio Usage between Hydrator 3.3 and Fatliquor 5.0?

1. Hydrator 3.3 to Fatliquor 5.0 ratio practice is 2 to 1, and it works out to be approximately 160gm of Hydrator 3.3 plus 80gm of Fatliquor 5.0 to replenish 100gm dry leather, from less than 1% back to the original tannery up from an average of 14% fatliquor content.
2. Fatliquor 5.0 by weight content comprised 16.66% ionic negative (-ve) charged fat and oil, encased in 83.33% water.
3. Fatliquor water content that encased the fat and oil molecule in an emulsion suspension when hydrogen bonds with the ionic positive (+ve) leather protein fiber break free and discharge clear from the leather structure to the surface.

  How to Lighten Leather Appearance after Drying from Fatliquoring on a Chanel Diamond Quilted Pattern Lambskin Bag?

Yes! Lightening the leather appearance after drying from fatliquoring is about physically manipulating the fibers to regain their natural softness and color vibrancy. Here’s a more refined step-by-step approach for a Chanel diamond-quilted lambskin bag:

Step-by-Step Lightening & Puffing Process

1. Ensure the Leather is Fully Dried

   • Allow the bag to air dry naturally after fatliquoring to prevent unwanted distortions.

2. Use a Smooth Spatula or Teaspoon

   • A smooth, rounded edge (like the back of a teaspoon) helps stretch the leather gently without causing damage.

3. Stretch from Center to Stitching

   • Place the tool in the center of each quilted diamond and press outward towards the stitching.
   • This motion helps loosen up the fibers, enhancing puffiness and restoring the lightened effect.

4. Apply Controlled Pressure

   • Moderate pressure is key—too much can cause over-stretching, while too little won’t achieve the desired effect.
   • The goal is to encourage fiber movement without distorting the stitching pattern.

5. Buff & Refine

   • After stretching, lightly buff with a soft microfiber cloth to even out the finish.
   • If needed, a final application of a Leather Doctor® finishing can restore luster with Gloss 21.

This technique helps maintain the softness, puffiness, and luxurious look characteristic of Chanel lambskin. Would you like product recommendations for aftercare?

14 Tips:

1. Always pre-condition the leather/nubuck/suede with Hydrator 3.3 to relax, and open up the fiber structure before Fatliquor 5.0.
2. A fully fat liquor replenished leather maintains an average of 14% fat and oil content, while vegetable-tanned leather is more thirsty.
3. Insufficient fat-liquoring (fat and oil) content may remain stiff and suffer cracking from staking, massaging, or flexing.
4. When crispy dry, prior surface contamination or damages may darken with resurfaced soiling particulates.
5. Removes surface soiling particulates with Eraser 4 for all leathers including nubuck and Eraser 5 for suede.
6. Stretching the dark areas lightly will also lighten the appearance.

15 Product Reviews - Posted by Larry Bauman on 31st Jul 2017 -The Lazarus Effect https://leatherdoctor.com/sheepskin-care-kit-sr3/#product-reviews

This product revived my 40-year-old Sheepskin coat that cracked at the touch of it after applying another company's 'Restoration' product. That other product ruined my coat, and I was about to throw it away but took a chance on the Leather Doctor. After applying Hydrator 3.3, I saw an immediate change. I then continued with the Fatliquor 5.0 and was shocked to see the change. My coat is now as soft and supple as it was when I purchased it in 1975! Don't even take a chance on valuable leathers with other companies' products, this one will amaze you with its results.

Your opinions and insights are precious and will help us solve your leather problem more efficiently. 

Edited: March 21, 2025, by Roger Koh