BERKSHIRE TESTS bond paper properties identified by contamination control professionals as most critical. The test methods we employ are vital to product development and quality assurance. All test methods are based on Recommended Practices and Standards from the Institute of Environmental Sciences and Technology (IEST), the International Organisation for Standardisation (ISO) and the Technical Association of the Pulp and Paper Industry (TAPPI).

The following are brief descriptions of Berkshire’s Bond Paper Tests:

Weight and Thickness

Basis Weight — A sample of bond paper, of known size, is weighed and results expressed as grams per square meter (g/m2). [TAPPI T-410]

Caliper — The thickness of a single sheet of bond paper is measured using a digital micrometer.  Results for thickness are expressed in microns (µm). [TAPPI T-411]


Fibers — A sample of bond paper is “sluiced” in a tray of water for one minute. The fibers released into the water are filtered onto a membrane and counted microscopically. The results are expressed as fibers ≥ 100µm per square centimeter of bond paper. [IEST-RP.CC020.2]

Particle Generation — A sample of bond paper is “sluiced” in a tray of water for one minute. A liquid-borne particle counter tallies the particles released into the water. By dividing the total number of particles released by the area of the bond paper sample, the results are expressed as particles ≥ 0.5µm per square centimeter of bond paper. [IEST-RP.CC020.2]


Non-Volatile Residue — Berkshire generates non-volatile residue data using both deionized water and 2-Propanol. Results are expressed in grams of extractables per square meter of bond paper. [IEST-RP.CC020.2]

Metallic Ions — Ions are extracted in deionized water and quantitatively analyzed by Ion Chromatography. Results are stated in parts per million (ppm). [IEST-RP.CC020.2]


Tear — The force required to tear bond paper is tested across the width and length of the sample.  Results are expressed in millinewtons (mN). [ISO 1974:2012]

Burst — The pressure required to burst bond paper is tested with results expressed in kilopascals (kPa). [ISO 2758:2014]