DIN EN ISO 12625-16:2024-09

This document specifies the testing procedures for the instrumental determination of the opacity of tissue paper or tissue products by diffuse reflectance using a paper backing. This document contains specific instructions for the preparation of test pieces of single-ply and multi-ply products, where special preparation/procedures might be necessary. It can be used to determine the opacity of tissue paper and tissue products containing fluorescent whitening agents, provided the UV content of the radiation incident on the test piece has been adjusted to conform to that in the CIE illuminant C using a fluorescent reference standard provided by an authorized laboratory as described in ISO 2470-1. This document has been prepared by Technical Committee ISO/TC 6 "Paper, board and pulps" in collaboration with Technical Committee CEN/TC 172 "Pulp, paper and board", the secretariat of which is held by DIN (Germany). The responsible German standardization committee is Working Committee NA 074-02-05 AA "Prüfverfahren für Tissue-Papier und Tissue-Produkte" ("Test methods for tissue paper and tissue products") at DIN Standards Committee Paper, board and pulps (NPa).