ISO 8791

Introducing ISO 8791 – Industrial Physics

ISO 8791 is the international standard series for determining the roughness and smoothness of paper and paperboard. These methods evaluate how air flows across or through the surface of a sheet under controlled conditions, providing essential insight into surface texture, coating quality, printability, and converting performance.

Surface roughness is a critical parameter for printing grades, packaging board, coated papers, and specialty materials — influencing ink laydown, gloss, coating holdout, and overall visual appearance.

What ISO 8791 Covers

ISO 8791 consists of several parts, each defining a different method for measuring surface roughness or smoothness. Across the series, the standard specifies:

• Controlled airflow‑based measurement techniques
• Defined clamping pressures and geometries
• Calibration using certified airflow restrictors
• Conditioning requirements for temperature and humidity
• Reporting results in mL/min, µm, or method‑specific units

The methods apply to:

• Coated and uncoated printing papers
• Paperboard and cartonboard
• Packaging grades
• Papers requiring controlled surface texture for print and coating performance

ISO 8791 ensures consistent, comparable surface‑roughness measurements across laboratories and production environments.

Where ISO 8791 Is Used

This standard is widely used across the paper and packaging supply chain:

• Paper mills and coating operations
• Printing‑grade producers
• Packaging‑board manufacturers
• Quality‑control laboratories
• R&D and formulation teams
• Customer‑specification and compliance testing

It supports both routine production monitoring and comparative evaluation of surface quality.

Why Surface‑Roughness Testing Matters

Understanding surface roughness is essential for:

• Ensuring consistent printability and ink laydown
• Optimising coating formulation and application
• Controlling gloss, appearance, and surface uniformity
• Predicting press performance and converting behaviour
• Meeting industry and customer specifications

Airflow‑based roughness testing is a cornerstone of appearance‑ and performance‑based quality control.

Testing solutions for ISO 8791

Three products from the Featured Products section align with ISO 8791’s focus on airflow‑based surface‑roughness and porosity measurement:

Profile Plus Porosity

A high‑precision airflow‑based porosity and surface‑evaluation module engineered for accurate measurement of paper structure and surface characteristics. Ideal for ISO 8791 applications, it delivers stable, repeatable results across a wide range of paper grades.

Profile Plus Porosity – Calibrated Air‑Flow Restrictor (High Range)

A high‑range restrictor designed for testing rougher, more open‑structured papers and boards. This calibrated module extends the measurement capability of Profile Plus Porosity systems while maintaining ISO‑aligned accuracy.

Profile Plus Porosity – Calibrated Air‑Flow Restrictor (Low Range)

A low‑range restrictor ideal for fine, dense, or highly coated papers where low airflow values must be measured with precision. Perfect for premium printing grades and smooth coated surfaces.

Your Global Test and Measurement Partner for ISO 8791

Industrial Physics supports paper manufacturers, converters, and laboratories with the tools and expertise needed to evaluate surface performance in line with ISO 8791. From airflow‑based roughness testing to full optical and physical‑property analysis, we help ensure your materials meet demanding print and performance standards.