# ISO 3688:1999 — Withdrawn and superseded ISO standards

For ISO 3688:1999, item title is Pulps — Preparation of laboratory sheets for the measurement of diffuse blue reflectance factor (ISO brightness); status code is 9599; successor is ISO 3688:2022; withdrawn / published date is 1999-03-11, recorded from its source on 2026-08-05.

- **Identifier:** ISO 3688:1999 _(verified: appears in the quote below)_
- **Item title:** Pulps — Preparation of laboratory sheets for the measurement of diffuse blue reflectance factor (ISO brightness) _(verified: appears in the quote below)_
- **Status code:** 9599 _(verified: appears in the quote below)_
- **Successor:** ISO 3688:2022
- **Withdrawn / published date:** 1999-03-11 _(verified: appears in the quote below)_

## What the source says

> 9155,IS,,ISO 3688:1999,Pulps — Preparation of laboratory sheets for the measurement of diffuse blue reflectance factor (ISO brightness),Pâtes — Préparation des feuilles de laboratoire pour le mesurage du facteur de réflectance diffuse dans le bleu (degré de blancheur ISO),1999-03-11,2,['85.040'],ISO/TC 6,9599,"[9156,9154]",[81615],"['en','fr']",5,"<p>This International Standard specifies two procedures for the preparation of laboratory sheets prior to measuring the<br />diffuse blue reflectance factor (ISO brightness). One is the traditional procedure based on preparation of sheets in a<br />Büchner funnel using a filter paper or a wire screen. ln the other procedure, the sheets are prepared

## Source

- https://isopublicstorageprod.blob.core.windows.net/opendata/_latest/iso_deliverables_metadata/csv/iso_deliverables_metadata.csv

Last verified: 2026-08-05. Review by: 2027-02-01.
Part of [Withdrawn and superseded ISO standards](https://referencesource.org/iso-standard-supersessions/).