Overview
ISO 8254-1:2009 - Paper and board - Measurement of specular gloss - Part 1: 75° gloss with a converging beam (TAPPI method) defines a standardized laboratory method for measuring the specular gloss of paper and board at an incidence/reflection angle of 75° using a converging beam (TAPPI geometry). Its chief application is to coated papers, but it is also suitable for glossy uncoated grades such as supercalendered papers. The standard describes instrument geometry, calibration, sampling, test-piece preparation, measurement procedure, precision and test reporting.
Key Topics and Requirements
- Measurement geometry: Specular gloss measured at 75° to the normal with a converging beam; the geometry and optical aperture are defined in Annex A.
- Apparatus: A gloss meter (reflectometer) with a light source, converging lens, photodetector and a matt-black light-tight housing.
- Gloss standards:
- Primary theoretical standard: ideal plane mirror (assigned 384.4 gloss units); black glass is used as a 100-unit reference (refractive index 1.540 at 587.56 nm).
- High-gloss, intermediate-gloss and working standards for calibration and instrument checks.
- Zero-gloss standard: black cavity or matt-black surface for zeroing the instrument.
- Calibration procedure: Zero check, adjust against high-gloss reference, verify with intermediate-gloss standards; adjust if readings differ by more than 1 gloss unit.
- Sampling & preparation: Cut at least ten test pieces sized to cover the instrument aperture, condition at 23 °C and 50 % RH (ISO 187), and avoid handling the test area.
- Limitations: Not intended for cast-coated, lacquered, heavily varnished or waxed papers and some high-gloss ink films - measurements at other angles (e.g., 20°) may be preferred.
Applications
- Routine quality control of coated and glossy uncoated papers in mills and converting plants.
- Specification and acceptance testing for paper suppliers and printers where surface gloss affects appearance or print performance.
- Product development and coating formulation where gloss targets must be achieved.
- Calibration and validation of gloss meters used in paper and packaging laboratories.
Who uses this standard
- Paper and board manufacturers, coating formulators, converters and packaging suppliers
- Printing houses and prepress/quality assurance teams
- Test laboratories and instrument manufacturers producing gloss meters
- Procurement and quality engineers specifying surface appearance
Related standards
Keywords: ISO 8254-1:2009, specular gloss, 75° gloss, TAPPI method, gloss meter, paper and board, coated paper, calibration, gloss standards.
Open preview (PDF)Paper and board — Measurement of specular gloss — Part 1: 75 degree gloss with a converging beam, TAPPI method