Aniline Leather Shrinkage and Topcoat Refinishing Kit ST.tc by Leather Doctor clean, pH balance, hydrates, softens, and restores shrinkage with topcoat refinishing.
What is Leather Shrinkage Caused by Alkaline Overexposure?- Alkaline overexposure causes the leather denaturing where the leather constituents like the tanning agent and the fatliquor break the hydrogen bond and leach out.
- The tanning agent leather out causes the leather to become tacky when wet.
- The fatliquor leaches out causing the leather to shrink and become stiff, and when flex cracks.
How to Remove Alkaline Contamination?- Alkaline contamination must be removed and the leather pH-balanced with a low pH system.
- Low pH balancing increases the effective hydrogen bonding between the ionic positive (+ve) leather fiber and the ionic negative (-ve) leather constituents like the tanning agent and the fatliquor.
- A squeaky healthy feel indicates that the leather is pH balanced and the wet leather is proceeded with shrinkage restoration.
How to Restore the Shrinkage?- Shrinkage is restored by hydrating the shrunk leather to relax, becoming limp, and plump enabling it to be gently stretched back to its original dimension.
- Fatliquoring in sync with hydrating helps lubricate the stick-together fiber to expand and stay separated sliding one over another smoothly without breaking.
- The softness and suppleness of the leather when dry depends on the percentage of the fat and oil remaining in the leather after drying, thus repeat application once the water content evaporates.
- When the desired dimension is achieved, the fat-liquored leather is left to natural drying.
- Sticky residue is wiped off with Hydrator 3.3 and ready for goss top coating when dry.
How to Restore the Gloss or Matte Topcoat?- A gloss or matte topcoat is applied and dry between coats to match.
Kit ST.tc concentrates contents require 1125g (1.3 quarts) distilled water to be mixed and filled before use with these selected leather-safe products:
✅ pH 1.5
✅ Acidifier 2.0
✅ Hydrator 3.3
✅ Fatliquor 5.0
✅ Gloss 76
✅ Protector B
✅ Brush 1
✅ Foam 2
✅ Towel 5
Leather pH Cleaner 1.5 by Leather Doctor® is a pH 1.5 balanced specialty cleaner that controls leather from bleeding, water spots, and becoming sticky.
pH 1.5 Key Benefits:
- pH 1.5 is a low pH (1.5) ionic, negatively charged (-ve) water-based restorative cleaner specially designed to neutralize and balance side effects on leather and suede caused by alkaline overexposure—such as bleeding, discoloration, or stickiness.
- Leather has a natural pH range of 3 to 5.
- When exposed to products with high pH (alkaline)—like saddle soap, baking soda, dish detergent, above pH 7, or harsh commercial cleaners—the leather structure becomes denatured, leading to long-term damage.
- pH 1.5 reintroduces acidity (extra H⁺ ions) to protonate the protein fibers, helping to restore the leather’s integrity and bring it back to its healthy, pH-balanced state.
Leather Acidifier 2.0 by Leather Doctor® is a professional-grade pH 2.0 acidic rinse scientifically designed to restore and maintain leather’s natural pH balance.
- Overexposure to alkaline products (such as soaps, detergents, ammonia, saddle soap, or baking soda) weakens leather fibers, causes browning, dye bleeding, streaking, and tackiness, and accelerates structural damage.
Acidifier 2.0 neutralizes alkaline contamination, restores smoothness, and reinforces leather strength—keeping your investment in premium leathers healthy, supple, and long-lasting.
Key Benefits
- Neutralizes alkaline residues from cleaners, sweat, and body oils
- Prevents dye bleeding, streaking, and browning discoloration
- Reduces tackiness and restores natural texture
- Strengthens leather fibers to resist structural weakening
- Essential pH balancing step in leather restoration care
Leather Hydrator 3.3 by Leather Doctor® is a professional-grade, pH 3.3 aqueous surfactant solution designed to clean, hydrate, relax, and restore leather’s internal structure.
Based on Tannery Science, this unique formula replicates the hydration stage of leather pre-conditioning, making it essential before fatliquoring with Fatliquor 5.0.- When leather becomes stiff, dry, or shrunken, the fibers collapse and bond together.
- Hydrator 3.3 penetrates deeply, rehydrates the collapsed fibers, balances the pH, and prepares the structure for deep conditioning.
- It also helps suspend and wick out impurities such as body oils, sweat, alkaline residues, and embedded soiling that compromise softness and flexibility.
- Unlike water alone, Hydrator 3.3 reduces surface tension, ensuring deeper fiber penetration and uniform hydration.
- This critical pre-conditioning step restores suppleness, prevents patchiness, and maximizes the effectiveness of Fatliquor 5.0.
Hydrator 3.3 Key Features & Benefits:-
Rehydrates Stiff or Collapsed Fibers – Restores essential moisture to dried-out or aged leather.
- Prepares for Fatliquoring – Opens the leather’s fiber structure so Fatliquor 5.0 can penetrate and bond effectively.
- Balances pH (3.3) – Realigns ionic charges to prevent alkaline damage and improve fatliquor absorption.
- Suspends & Flushes Impurities – Helps wick out sweat, body oils, soiling, and chemical residues from within the fibers.
- Restores Suppleness & Softness – Reduces stiffness and ensures even conditioning results without patchiness.
- Tannery-Science Formula – Replicates the professional hydration step used in tanning and re-tanning processes.
- Versatile Use – Suitable for vachetta, nubuck, suede, aniline, full-grain, pigmented, vegetable-tanned and hair-on-hide leather.
Leather Fatliquor 5.0 by Leather Doctor® is a pH 5.0 emulsion of fat, oil, and water conditioner / fatliquor / softener for replenishing dry leather, in line with its tannery science-based function.
It restores leather’s internal lubrication, flexibility, strength, and resilience, replenishing the original fatliquor content of leather’s fibrous structure—mimicking the essential fatliquoring stage in professional tanning and retanning processes.
- Fatliquor 5.0 Plus is the leather scent version.
Fatliquor 5.0 Key Benefits:
- Lubricates and nourishes the leather structure
- Fatliquor 5.0 deposits fat and oil molecules that bond to the amphoteric protein fibers.
- These lubricate the fibrils, allowing them to slide over each other without stiffness, brittleness, or cracking.
- Reinforces tensile strength and elasticity
- Proper fatliquoring prevents fiber embrittlement and maintains leather’s natural strength and softness.
- Restores suppleness and prevents future damage
- Leather loses fatliquor over time due to aging, heat, sunlight, alkaline exposure, or cleaning.
- Replenishing it prevents shrinkage, stiffness, and cracks.
- Provides long-term structural protection
- Maintains leather’s dimensional stability and ability to flex without damage.
Tannery Science Basis:
- In the tannery, fatliquoring is one of the final and most critical stages after tanning and dyeing.
- It ensures that leather stays soft, strong, and flexible as it dries.
- The fats and oils form a molecular film around the protein fibers, acting as internal lubricants.
- Fatliquor 5.0 brings this same process to leather restoration.
- It ensures the leather is not just “looking good on the surface” but structurally rejuvenated from within.
It prevents color crocking and bleeding while enhancing the leather's appearance with a clear, high-gloss finish.
Gloss 76 features: High-Gloss Protective Topcoat for Aniline Leathers
- Heavy-Duty Protection – Formulated for maximum toughness and flexibility.
- Crystal-Clear Gloss – Fine particulate urethane-resin emulsion delivers a sleek, glossy finish.
- Versatile Use – Perfect for upholstery, handbags, garments, and boots.
- Customizable Durability – Boost water resistance and resolve tackiness by adding Crosslinker 64 at a 1:95 weight ratio.
Matte 21 provides a matte luster and a distinct waxy feel, perfectly suited to preserve and enhance waxed aniline leathers while maintaining their natural aesthetic and soft texture.
This wax-enriched topcoat is ideal for upholstery, handbags, garments, and saddlery, offering superior durability, flexibility, and resistance against friction, oxidation, and dye migration.
Matte 21 Key Features:
- Matte finish with a waxy feel of hand.
- Tough and flexible urethane resin formulation.
- Seals and protects aniline dyes.
- Retains the natural look and softness of the leather.
- Recommended for professional-grade refinishing and rejuvenation.
Leather Protector B by Leather Doctor® is a pH 3.2 non-stick, rub-resistant conditioner scientifically formulated to enhance durability, prevent friction wear, and protect smooth leather surfaces. It creates a soft, buttery feel while preserving leather’s natural breathability and flexibility.
Leather Protector B – Smooth Leather’s #1 Choice
Key Benefits of Protector B:
- Increases Wet & Dry Rub Resistance – Minimizes stretch, scuffing, and wear.
- Enhances Durability – Builds a shield against everyday abrasion and friction.
- Prevents Sticky Soiling – Stops dirt and stains from embedding into the leather.
- Resists Ink & Dye Transfer – Helps release ballpoint ink marks and dye stains.
- Reduces Friction Noise – Improves the touch with a smooth, quieter glide.
- Imparts a Non-Sticky Surface – Eliminates tackiness for a refined feel.
- Maintains Leather’s Breathability – Keeps leather soft, supple, and flexible.
Protector B Plus – With Leather Scent
- For those who enjoy a subtle fragrance, B Plus combines all the protective benefits of Protector B with a luxurious leather scent.
- Perfect for pastel leathers that need extra resistance against stains while staying fresh.
Leather Protector W by Leather Doctor® is a matte, waxy-feel, non-stick, rub-resistant conditioner designed for waxed aniline, and split-suede leathers. It maintains the leather’s natural elegance without artificial gloss, while enhancing durability and everyday resistance.
Protector W – For Waxed Leathers
Key Benefits of Protector W:
- Matte, Waxy-Feel Conditioning – Preserves a natural, sophisticated look.
- Non-Stick Formula – Prevents sticky soiling and keeps dirt from embedding.
- Rub-Resistant Protection – Minimizes wear, scuffing, and stretching.
- Refined Appearance – Protects leather while keeping its authentic finish.
- Ideal for High-Contact Surfaces – Perfect for steering wheels, saddlery, and waxed aniline leather furniture.
W Plus – With Leather Scent
For a touch of refinement, Protector W Plus adds a luxurious leather scent to all the protective benefits of Protector W, making it a favorite for waxy leathers in frequent use.
Instruction: - Pro 1.5 concentrate has to be mixed with distilled water before use.
- Apply Pro 1.5 and agitate with horsehair Brush 1 and towel extract until the towel shows clean, and proceed with Acidifier 2.0.
- Acidifier 2.0 concentrate has to be mixed with distilled water before use.
- Apply Acidifier 2.0 and agitate with horsehair Brush 1 and towel extract until the towel shows clean.
- Inspect the unwanted tacky feel diminished and is replaced with a healthy squeak feel otherwise repeat the above process with dwelling, and proceed with hydrating.
- Hydrator 3.3 concentrate has to be mixed with distilled water before use.
- Apply, and work into cleaned leather.
- Accelerate saturation by working on the reverse side, micro-cracks, stitching seam, or perforated panel for a darkening effect.
- Optional thorough saturation is achieved by covering with a soaked-up stretchable Towel 5.
- Allow 1 to 48 hours of dwelling for effective relaxing results.
- Physical massaging, stretching, pulling, and stretching help return the shrinkage to dimension, and combine with fatliquoring by introducing fat and oil into the leather simultaneously to ease the restoring process.
- Fatliquor 5.0 concentrate has to be mixed with distilled water before use.
- Apply and redistribute with appropriate brushes or pads until the thickness of the leather is saturated.
- Repeat each time water contents evaporate leaving behind only the fat and oil content.
- Sticky residue is further driven into the leather structure or rinsed off until surface milky fat and oil turn clear with Hydrator 3.3.
- Allow natural drying for extra softness.
- Suppleness of leathers is further staked, massaged, or flexed accordingly with a little wet back with Hydrator 3.3 until dry.
- Gloss 76 or Matte 21 concentrate has to be mixed with distilled water before use.
- Use lint-free padding, foam brush, varnishing brush, or airbrushing for a professional result.
- Blow dry in between applications.
- Protector B or W concentrate has to be mixed with distilled water before use.
- Shake well, apply, and spread with a lint-free towel and it is ready to use when dry.
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Created Aug 15, 2024 | September 21, 2025 by Roger Koh
