CIE Whiteness, Illuminant D65, UV Adjusted and Excluded

This test is performed to determine the CIE Whiteness at D65/10° of paper, solid board or folding board. The diffuse reflectivity of the material is determined under standardised conditions after adjustment of the instrument so that the relative UV-content of the illumination corresponds to that of the CIE standard D65 Illuminant, and the CIE Whiteness is calculated

Operate the instrument in accordance with ISO 2470-1 and the manufacturer’s instructions.

Leave the samples exposed for 24 h to 23°C and 50% R.H., according to ISO 187.

Calibrate the instrument according to the instrument maker’s instructions, using a non-fluorescent ISO reference standard of level 3 (IR3). Adjust the UV-content to the D65/10° Illuminant/observer.

Each sample pack is made of a pad of paper to be tested and a coloured cover sheet.

Remove the coloured protective sheet from the test piece pad.

Place the test piece in the position indicated on the cover sheet.

Without touching the test area, use the procedure appropriate to the instrument to measure the CIE Whiteness of the top side of the test piece pad without and with the UV (D65) 420 cut-off filter.

Read and record the measures.

Move the measured test piece to the bottom of the pad and determine the CIE Whiteness for the next and similarly for the following test pieces until at least ten test pieces have been measured.

Report 10 measures of the CIE Whiteness in %, their mean and standard deviation calculated to 3 significant figures.