| Lightfastness rating | Blue Wool scale rating from 1 to 8 | ISO 105-B02 uses blue wool references: 1 = very low lightfastness; 8 = exceptional lightfastness. | Prefer rating 6–8 for leashes regularly used outdoors; rating 4–5 may be suitable for moderate exposure. | A higher rating indicates better resistance to fading caused by xenon-arc light that simulates important components of daylight. |
| Test method | Xenon-arc exposure under a specified ISO 105-B02 procedure | The test compares specimen fading with the defined blue wool references. The selected method, irradiance, filters, humidity, and evaluation conditions must be recorded. | Accept only results that identify the exact ISO 105-B02 method and conditioning details. | A lightfastness number without test conditions is difficult to compare reliably between materials or laboratories. |
| Exposure duration | Hours or radiant exposure reported by the laboratory | ISO 105-B02 does not provide one universal exposure time for every material; exposure is controlled and evaluated against the blue wool references. | Compare samples only when the exposure program and endpoint are equivalent. | Different exposure programs can produce different apparent durability results even when the textile is identical. |
| Color change after exposure | Visual or instrumental change after UV exposure | The final lightfastness grade is determined by comparison with the blue wool scale, not by color name alone. | Prefer a high blue wool rating and no obvious uneven fading, streaking, or surface chalking. | Uneven fading may indicate inconsistent dye penetration, coating degradation, or localized UV sensitivity. |
| Breaking strength retention | Percentage of tensile strength remaining after light exposure | Retention (%) = exposed breaking strength ÷ unexposed breaking strength × 100. | Use the buyer’s safety specification; as a screening guide, prioritize samples retaining at least 80% of initial breaking strength. | A leash can retain its color while the polyester yarn or stitching has lost mechanical strength. |
| Webbing construction | Webbing width, thickness, weave uniformity, and edge condition | Not assigned a pass/fail value by ISO 105-B02; inspect separately before and after light exposure. | Choose dense, even webbing with no exposed filaments, skipped yarns, sharp edges, or visible thinning. | UV degradation is more concerning when the webbing already contains weak points or damaged edges. |
| Stitching and load areas | Stitch density, reinforcement pattern, and condition after exposure | Record any broken, loose, discolored, or embrittled threads after testing. | Prefer reinforced box-X or equivalent load-bearing stitching with no visible thread failure. | Handle joints, clip loops, and adjustment points typically experience concentrated loading. |
| Hardware condition | Clip operation, spring action, corrosion, cracking, and attachment integrity | Hardware is not rated by ISO 105-B02; assess it as a separate component before and after exposure. | Reject any clip that sticks, opens unintentionally, cracks, develops sharp corrosion, or loosens at the webbing joint. | The leash system can fail at the clip or attachment even when the polyester webbing remains intact. |
| Moisture and cleaning history | Conditioning procedure, washing method, and number of cleaning cycles | Record conditioning and cleaning separately from the ISO 105-B02 exposure because moisture and detergents may affect appearance and strength. | Prefer products with documented care instructions and no residual stiffness, odor, or coating damage after cleaning. | Outdoor leashes are commonly exposed to water, dirt, salt, and repeated cleaning in addition to sunlight. |
| Decision record | Laboratory, test date, specimen description, rating, and observations | A valid comparison should include the ISO 105-B02 edition or method, blue wool rating, exposure conditions, and specimen identification. | Select the leash with the strongest documented combination of lightfastness, strength retention, construction quality, and hardware security. | Traceable records reduce the risk of choosing a product based only on color or an unsupported UV-resistance claim. |