These surface optical properties are used in most specifications to define the visual quality of plastic, paper and board. The tests can be made on a range of materials including plastic, tissue, paper, copy paper, coated board, carton board and papers for most printing applications.
Technidyne Colourtouch PC Spectrophotometer
CIE whiteness, brightness, L*a*b* colour and opacity are all measured using a Technidyne Colourtouch PC spectrophotometer with a range of light sources.
Smithers Pira's UKAS, ISO 17025 accredited testing is performed to the following British standard and International standards: whiteness to BS ISO 11475; brightness to BS ISO 2470; colour to ISO 5631 and opacity to BS ISO 2471.
Testing of all of these properties is included in Smithers Pira's Paper Proficiency Service .
EEL 12M Opacimeter
Opacity and whiteness are measured as a percentage using the EEL 12M Opacimeter. An internal microprocessor compares the diffuse reflectance of the sample against black and white references to give opacity.
The EEL Opacimeter is used to measure opacity of plastic using a method based on the Packaging and Industrial Films Association (PIFA) Voluntary Standard 3/79.