ISO 8254-2:2016

Overview

ISO 8254-2:2016 - "Paper and board - Measurement of specular gloss - Part 2: 75° gloss with a parallel beam, DIN method" - specifies a photometric test method to assess visual specular gloss of plane paper and board using a 75° incidence angle with a parallel (collimated) beam reflectometer (the DIN method). It applies to surfaces with gloss values below 65 and is the preferred method for matt papers (gloss < 20). Materials containing optical brightening agents can be measured.

Key topics and technical requirements

• Measurement principle: Illuminate the sample with a collimated beam at 75° to the normal; measure reflected light in a defined solid angle centred on the specular direction. The instrument returns a reflectometer value proportional to the integrated reflection indicatrix.
• Equipment: Reflectometer composed of a collimator, decollimator, light source, photoelectronic receptor and sample holder (see normative Annex A).
• Calibration and gloss standards:
  • Zero-gloss standard (e.g., black cavity).
  • Primary gloss standard (black glass plate or fused quartz wedge with defined refractive index; assigned value 100).
  • Working standards (flat non‑fluorescent surfaces, R ≈ 80–100).
  • Intermediate standards (assigned values 0–100; an intermediate ≈20 is required).
  • Gloss standards should be checked at least once per year.
• Sampling and preparation:
  • Sampling for lot averages: follow ISO 186.
  • Conditioning: 23 °C and 50 % RH per ISO 187; maintain climate during testing.
  • Prepare ≥5 test pieces per side, free from scratches, dust or handling marks; avoid touching measured surface.
• Procedure elements: Instrument calibration, determination of reflectometer value, calculation and reporting of results. Annex B lists organizations for calibration of intermediate standards.
• Limitations: Precision data were not available at publication; reflectometer values are comparable only when measured with the same geometry.

Applications

• Quality control and specification of paper and board surface appearance (matt, satin, glossy grades).
• Incoming inspection for coated papers and substrates used in printing and packaging.
• Process control for paper/coating mills, converters and finishing operations to monitor surface gloss consistency.
• Laboratory testing and certification of paper products for product datasheets and procurement.

Who uses this standard

• Paper and board manufacturers
• Coating formulators and converters
• Printing and packaging quality managers
• Independent testing laboratories and certification bodies
• R&D teams evaluating surface finishing and optical performance

Related standards

• ISO 8254-1 (75° converging beam, TAPPI method)
• ISO 8254-3 (20° gloss with converging beam, TAPPI method)
• ISO 186 (sampling)
• ISO 187 (conditioning)
• EN 14086 (45° measurement reference)

Keywords: ISO 8254-2, specular gloss, 75° gloss, reflectometer, DIN method, paper testing, paper and board, gloss measurement, ISO paper standards.