In the leather industry, analysis of the application of different dyes on different leathers is based on their characteristics

Acid dyes (accounting for about 45% of leather dyes, mainstream)

Core features

Structure: Included Sulfonic acid group (-SO₃H) / Carboxyl group (-COOH) , water-soluble anions, small molecules, strong permeability.

Bonding: Acidic medium (pH 3.5–5.5) binds to collagen ** amino (-NH₂)** ionic bonds, Excellent dye penetration 。

Category:

Pros and cons: Chromatography is complete, vivid, good penetration, and medium-to-high lightfastness ； Wet wipe / Sweat stains have average adhesion, needs color fixation.

Suitable for leather

✅ chrome tanned leather (Cow / Sheep / Pig light leather ） : First choice: car interiors, sofas, clothing leather.

✅ Veg-tan Leather (pH adjusted to mildly acidic) : Can be dyed, light to medium dark colors.

✅ Fur (rabbit / sheep) : Evenly dye the fur and leather board.

❌ High-cation tanned leather (such as aluminum tanning) : Charge repulsion, poor upper dyeing.

Metal Complexation Dyes (1:1/1:2 type, high-end mainstream)

Core features

Structure: Dye complexed with **Cr³⁺/Co²⁺**, 1:1 (strongly acidic), 1:2 (weakly acidic/neutral).

Combination: ionic bonds + complexation stability, Large molecules, medium penetration, top-level fastness 。

Pros and cons: Lightfastness (≥7 grade), moisture rub resistance, migration resistance, heat resistance ； The color tends to be darker and the cost is higher.

Suitable for leather

✅ High-end chrome tanned leather (Automotive/Aviation interiors, sofas, shoe uppers) : First choice, long-term durability.

✅ Suede / Suede leather : Black / dark brown has high lightfastness requirements.

✅ fur (high-end) : The fur does not fade, and the leather is soft.

❌ Light colors and bright colors are needed : Not as bright as acid dyes.

Direct Dyes (Main Surface Coloring)

Core features

Structure: Long-chain linear macromolecule, Water-soluble anions , weak penetration, strong surface adsorption.

Integration: Van der Waals forces + hydrogen bonds , No strong acid required, can be dyed neutrally or mildly alkaline.

Pros and cons: Good even dyeing, easy color matching, strong coverage, and low price ； Poor wet fastness, average light resistance, and easy migration.

Suitable for leather

✅ chrome tanned leather (Surface color touch-up / color correction) : Combined with acid dyes, solves surface color differences.

✅ Veg-tan Leather (dark color) : Direct dyeing, low cost.

✅ Double-layer leather / recycled leather : Strong coverage, high cost performance.

❌ Completely transparent / High Durability requirements : Surface coloring only.

Alkaline dyes (basic dyes, Veg-tan Exclusive)

Core features

Structure: Cationic type (Contains – NH₃⁺), moderate water solubility, solubilized by alcohol/acetic acid.

Binding: alkaline medium and… Veg-tan Hide Tanned anion Ionic bonding Wear The color is extremely strong and vivid 。

Pros and cons: Comprehensive chromatography, high brightness, and low cost ； Extremely poor sun and friction resistance, easy migration, and severe surface staining

Suitable for leather

✅ Veg-tan Leather (Handicrafts / Bags / Upper Shoes) : First choice, bright light colors.

✅ Synthetic tanned leather (such as urea) : Cations adsorb quickly, requiring slow dyeing.

❌ chrome tanned leather (Cation repulsion) : Almost no dye.

❌ Weather-resistant / durable scenarios : Fades easily, for short-term use only.

Reactive Dyes (Environmental Trend, Collagen Covalent Bonding)

Core features

Structure: Includes Active groups (such as trichlorotriazine) , can form with collagen amino groups Covalent bond (Permanent union).

Binding: Weakly alkaline (pH 7–8), Top-tier moisture resistance and fastness, non-migrate, environmentally friendly 。

Pros and cons: Extremely high durability, environmentally friendly, and soft to the touch ； High cost, requiring strict temperature control /pH and moderate permeability.

Suitable for leather

✅ chrome tanned leather (Environmentally friendly and high-end) : Clothing / furniture leather , formaldehyde-free, washable.

✅ Nude Skin / Veg-tan Hide : Direct covalent bonding, simple color fixation.

✅ Together finished leather (Contains amino groups) : For example, polyurethane leather enhances fastness.

❌ Low temperature / simple process : Requires 80–90°C, high energy consumption.

Alcohol-soluble / disperse dyes (combined finished leather / For painting purposes)

Core features

Alcohol solubility: Nonionic, insoluble in water, soluble in alcohol / ethylene glycol , with shallow penetration and surface coloration.

Disperse dyes: Ultrafine particles, non-ionic, high temperature (120–130°C) , fits nonpolar combination finished leather.

Pros and cons: It has good light resistance, is water-resistant, and suitable for spraying and finishing ； Poor permeability, requires solvent / high temperature.

Suitable for leather

✅ PU/PVC combined finished leather : Disperse dyes are used for high-temperature dyeing, with alcohol solubility used for coating and coloring.

✅ Leather Spraying / Color Correction (SP Series): Uniform surface with no color bleeding.

❌ Natural leather is fully transparently dyed : Insufficient penetration.

Dye-leather matching summary

Types of dyes	The best leather	Next, choose leather	The use of leather is prohibited	Core advantages	Typical uses
Acidic	Chrome tanning light leather	Veg-tan Leather and fur	Gaocation ion tanned leather	Good penetration, vivid colors, and high cost performance	Clothing, sofas, and shoe uppers
Metallic complexation	High-end chrome tanned leather	Suede and fur	Light-colored, vivid, and leather-colored leather	Top-tier lightfastness and moisture resistance	Automotive interiors and high-end shoe uppers
Directly	chrome tanned leather (Surface)	Veg-tan Leather, two-layer leather	Fully transparent and demanding reform	Evenly colored, strong coverage, and inexpensive	Color correction, color touch-up, luggage
Alkaline	Veg-tan Hide	and to craft tanned leather	chrome tanned leather	Extremely vibrant, low cost	Handicrafts, light-colored bags
Activity	Environmental protection chrome tanned leather	bare skin, Veg-tan Hide	Low-temperature craft leather	Covalent combination, extremely high rigidity, environmentally friendly	High-end clothing, furniture leather
Alcohol-soluble/dispersible	Together finished leather , decoration	Leather spraying	Natural fully transparent leather	Good lightfastness, suitable for surface coloring	PU leather, leather color correction

chrome tanned leather (Most general): Main choice Weakly acidic dyes (Penetration + fastness balance); For high-end use 1:2 metal complexation ; For surface color restoration Direct dyes 

Veg-tan Ge: light and bright selection Alkaline dyes ； Dark color selection Direct dyes ; Eco-friendly choice Reactive dyes 

Suede / Suede leather: Black / Dark Brown options Metallic complexation ; Bright color selection Weakly acidic 

Together finished leather (PU/PVC): For high temperatures Disperse dyes ; For decoration Alcohol-soluble dyes .

Environmental Trends: Priority Reactive dyes, low-metal acid dyes, chromium-free metal complexation dyes , complies with REACH / EU standards.