Leather Breathability Testing for Gloves: Air Permeability and Water Vapour Permeability Assessment

Breathability testing measures how efficiently glove leather transmits air and water vapour, a decisive factor for wearer comfort, dexterity, and regulatory compliance in work, sports, and fashion gloves. This article explains the principles, applicable standards, sample requirements, and test procedures — including ISO 14268, ISO 17229, GB/T 4689.21, and GB/T 4689.22 — used by accredited third-party laboratories to qualify glove leather. It also outlines typical applications, acceptance criteria, and frequently asked questions to support procurement, quality control, and certification decisions.

Technical Overview

Because gloves enclose the hand in a nearly closed microclimate, the ability of the leather to release heat and perspiration vapour directly determines wearing comfort. When breathability is poor, sweat accumulates inside the glove, causing skin maceration, loss of grip security, reduced dexterity, accelerated lining degradation, and in occupational settings a measurable increase in heat stress and skin irritation.

In leather testing, "breathability" covers two distinct transport mechanisms. Air permeability describes the convective flow of air through the interconnected pore structure of the leather under a pressure differential, while water vapour permeability describes the diffusive transfer of moisture molecules through and across the fibrous collagen network. Both properties depend strongly on the raw hide, the tanning and fatliquoring process, the thickness, and above all the type and load of finishing or coating applied to the grain surface.

Testing is harmonized through international and national standards. ISO 14268 specifies the dynamic determination of water vapour permeability, ISO 17229 covers water vapour absorption, and the Chinese national methods GB/T 4689.21 and GB/T 4689.22 address the air permeability and water vapour permeability of leather respectively. Gravimetric cup procedures adapted from ASTM E96/E96M and air permeability principles adapted from ASTM D737 are also widely applied. Product-level requirements are set by specifications such as GB/T 22864 for glove leather and by European protective glove standards such as EN ISO 21420 (which superseded EN 420), EN 388, and EN 659, which reference water vapour permeability assessment for leather glove constructions.

Testing Samples

Finished Glove Leathers

Representative samples of the finished leather used for glove uppers: full-grain cowhide and deerskin for work and driver gloves, goatskin for lightweight industrial gloves, sheep nappa for dress and fashion gloves, and pig split or suede leathers for economy and thermal linings. Typical thickness ranges from approximately 0.5 mm to 1.6 mm. Specimens are cut from positions agreed with the client, normally covering palm, back, and between-finger zones, and are identified as parallel or perpendicular to the backbone to account for the anisotropy of leather.

Coated and Finished Leathers

Leathers carrying polyurethane or acrylic coatings, heavy pigment finishes, or burnished glossy surfaces are tested separately from the base substrate. Because coatings can substantially obstruct the natural pore network, comparative testing of coated versus uncoated areas quantifies the comfort penalty introduced by surface finishing and supports coating formulation optimization.

Glove Components and Assemblies

Where the comfort of the finished article must be assessed, laboratories also test lining materials, waterproof membrane laminates, bonded leather-textile composites, seam sections, and complete glove panels. Assembly-level results combine the resistances of each layer and are more representative of real wear performance than substrate-only testing.

Testing Items

A standard breathability evaluation programme for glove leather typically includes the following items, selected according to the governing product standard or the purchase specification:

• Air permeability — convective airflow through the leather, expressed as volume per unit area per unit time (commonly mL/(cm²·h)), determined per GB/T 4689.21 or adapted air permeability procedures.
• Water vapour permeability (WVTR) — moisture transmission rate through the leather, expressed in mg/(cm²·h) per ISO 14268 or in g/(m²·24h) per gravimetric cup methods, tested per GB/T 4689.22 where applicable.
• Water vapour absorption — the capacity of the leather to take up moisture over a defined exposure period, determined per ISO 17229 and relevant to short-term sweat buffering.
• Complementary comfort indices — thermal resistance and water vapour resistance (Ret) of glove material assemblies per ISO 11092 (sweating guarded hotplate), and breathability retention after repeated flexing, where specified.

Testing Methods

Conditioning and Specimen Preparation

All specimens are conditioned in the standard leather atmosphere defined by ISO 2419 (23 ± 2 °C and 50 ± 5% relative humidity) for a minimum of 24 hours before testing. Circular or square specimens of the diameter required by the test cell — typically in the range of 30 mm to 100 mm — are cut free from defects, and at least three specimens per material are tested to characterize variability. Specimen thickness is recorded, as thickness strongly influences transmission results.

Air Permeability Testing

In the air permeability test per GB/T 4689.21, the specimen is clamped in a permeability cell and a defined pressure differential is applied across it. The volume of air passing through the unit area of leather in unit time is measured and reported as the air permeability. Adapted procedures based on ASTM D737 establish a fixed pressure drop across the clamped specimen and read the resulting flow rate. Highly dense, heavily coated leathers yield near-zero airflow, while full-grain and suede leathers show measurable permeation that correlates with ventilation performance.

Water Vapour Permeability — Dynamic Method (ISO 14268)

The dynamic method is the reference procedure referenced by European protective glove standards. A circular specimen is clamped as the lid of a permeability cup containing conditioned silica gel desiccant, with the test surface facing outward. The cups are mounted in a rotating carriage that produces a controlled air velocity across the specimen surface while the ambient temperature and humidity are held at the values specified by the method. As water vapour is drawn through the leather and absorbed by the desiccant, the cup gains mass. The water vapour permeability is calculated from the mass gain per unit area per unit time and reported in mg/(cm²·h). The rotating design eliminates stagnant air layers and yields reproducible, comparable results between laboratories.

Water Vapour Permeability — Gravimetric Cup Method

In the static cup approach, adapted from ASTM E96/E96M for leather, the specimen seals a cup containing either desiccant (desiccant method) or water (water method). The assembly is placed in a controlled humidity cabinet, and periodic weighing determines the moisture transmission rate, reported in g/(m²·24h). The water method additionally characterizes the wet-cup behaviour relevant to humid service environments. Results from cup methods and the dynamic method correlate, but conversion between them must be validated because the boundary conditions differ.

Water Vapour Absorption (ISO 17229)

For absorption testing, a conditioned specimen is exposed over water in a closed vessel for the defined exposure period. The increase in specimen mass, expressed per unit area, quantifies the hygroscopic buffering capacity of the leather. This parameter complements permeability data, since a leather with high absorption temporarily intercepts perspiration spikes even where steady-state transmission is moderate.

Data Evaluation and Reporting

The test report identifies the standard applied, sampling location and orientation, conditioning history, specimen thickness, individual and mean results with units, and any deviations. Where a specification limit applies, results are assessed against it directly. As indicative guidance, water vapour permeability values found in glove and upper-leather specifications commonly fall in the range of about 1 mg/(cm²·h) to 5 mg/(cm²·h); however, the applicable limit must always be taken from the governing product standard, certification scheme, or contractual specification, as requirements differ between industrial, protective, and fashion glove categories.

Applications

Breathability data for glove leather support decisions across the entire supply chain:

• Work and protective gloves — demonstrating compliance of leather materials with EN ISO 21420 and supporting certification of gloves to EN 388 against mechanical hazards, where wearer comfort and all-day acceptability depend on moisture management.
• Firefighting and heat-resistant gloves — qualification of leather components for EN 659 applications, where vapour transport must be balanced against thermal protection.
• Sports gloves — comfort engineering of cycling, golf, skiing, batting, and equestrian gloves, and optimization of perforated or membrane-lined constructions.
• Fashion and dress gloves — specification of nappa and suede leathers for dry, comfortable wear in form-fitting designs.
• Tannery process development — evaluating the effect of fatliquoring, retanning, milling, and finishing recipes on porosity and vapour transport.
• Procurement and trade — independent verification by accredited third-party laboratories for buyer specifications, factory audits, and import/export conformity documentation.

FAQ

Question: What is the difference between air permeability and water vapour permeability?

Answer: Air permeability measures bulk airflow through open pores under a pressure difference and reflects ventilation, whereas water vapour permeability measures molecular diffusion of moisture and reflects how sweat vapour escapes the glove. A leather may show low air permeability yet still acceptable water vapour permeability, because vapour can diffuse through the hygroscopic fibre structure even when convective pores are closed by finishing.

Question: Which standards should be applied for the European and Chinese markets?

Answer: For European protective glove certification, water vapour permeability is determined per ISO 14268 in the context of EN ISO 21420 and the relevant hazard standards. For the Chinese market, glove leather is evaluated per GB/T 4689.21 and GB/T 4689.22 together with the product requirements of GB/T 22864. Accredited third-party laboratories can confirm the correct combination for a specific product category.

Question: How much sample is required and how long does testing take?

Answer: Typically, three or more specimens per material with dimensions of roughly 60 mm to 100 mm are needed, or complete sample gloves from which specimens are cut. After the 24-hour conditioning period, testing usually takes a few working days, with overall lead times of about five to ten working days including reporting.

Question: How do coatings and finishes affect the results?

Answer: Surface coatings, heavy pigment finishes, and heavy burnishing can reduce air and water vapour permeability dramatically, sometimes to near-zero for continuous polyurethane films. Perforation, porous coatings, or film-free zones are common design countermeasures, and comparative testing before and after finishing quantifies their effectiveness.

Question: Can breathability testing be combined with other leather evaluations?

Answer: Yes. Breathability testing is routinely combined in a single test programme with thickness, tensile strength and elongation, tear strength, flex resistance, abrasion resistance, color fastness, and chemical safety parameters such as chromium(VI) and pH, giving a complete fitness-for-use profile of the glove leather.