Overview
EN ISO 8254-1:2009 - "Paper and board - Measurement of specular gloss - Part 1: 75° gloss with a converging beam, TAPPI method" is a CEN-adopted ISO method for quantifying the specular gloss of paper and board measured at a 75° angle using a converging-beam (TAPPI) geometry. Its primary application is to coated papers, but it is also suitable for glossy uncoated grades (for example, supercalendered papers). The standard defines the measurement principle, required apparatus, calibration procedures, sampling and conditioning, test procedure, precision and reporting.
Key topics and requirements
- Measurement geometry: Specular gloss measured at an incidence/reflection angle of 75° to the surface normal using a converging beam (TAPPI method).
- Scope limits: Not intended for assessing image-reflecting quality or extremely high-gloss surfaces such as cast-coated, highly varnished, lacquered or waxed papers - other angles (e.g., 20°) may be more appropriate.
- Apparatus essentials (Clause 5):
- Gloss meter/reflectometer with optical layout per Annex A.
- Light source and lens to produce a converging beam.
- Photodetector and a defined aperture to collect specular reflection.
- Test-piece holding device (e.g., suction plate) and a light-tight, matt-black housing.
- Standards and calibration:
- Primary specular reference: theoretical perfect mirror = 384.4 gloss units; a polished black glass with refractive index 1.540 at 587.56 nm acts as the 100 gloss unit reference on this scale.
- Calculation of high-gloss reference values can be derived from the glass refractive index (reference wavelength set to helium d line 587.56 nm).
- Measurement output: A specular gloss value-a dimensionless reflectometer value proportional to the luminous flux reflected into the defined aperture and scaled relative to the reference standard.
- Supporting procedures: Sampling (ISO 186), conditioning and atmosphere (ISO 187), calibration, precision assessment and requirements for test reporting.
Applications and users
- Quality control and QA in paper and board manufacturing
- Coating and finishing process control for coated paper producers
- Printing and converting operations monitoring surface gloss for print appearance
- Lab and instrument manufacturers validating and calibrating gloss meters
- R&D teams assessing formulation or process changes that affect surface gloss
Keywords naturally relevant for SEO: EN ISO 8254-1:2009, specular gloss, 75° gloss, TAPPI method, gloss meter, paper and board, coated papers, supercalendered paper, gloss calibration.
Related standards
- ISO 8254-2: 75° gloss with a parallel beam (DIN method)
- ISO 8254-3: 20° gloss with a converging beam (TAPPI method)
- ISO 186 (sampling) and ISO 187 (conditioning and atmosphere) - normative references used with this method.