ISO INTERNATIONAL STANDARD 3668 Third edition 2017-05 Paints and varnishes Visual comparison of colour of paints Peintures et vernis - Comparaison visuelle de la couleur des peintures Reference number IS0 3668:2017(E) os1 =ZHEJIANG INST OF STANDARDIZATION C15956617 @IS02017 vided by IHS underI itted without license from IHS IS0 3668:2017(E) COPYRIGHTPROTECTEDDOCUMENT IS0 2017, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISOcopyrightoffice Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 [email protected] www.iso.org Internatinair PrganizationforStandardization icensee-ZHEJIANG INSTOF STANDARDIZAoISQ07 -All rights reserved Not for Resale, 2017/8/21 01:45:03 etworking permitted without license from IHS IS0 3668:2017(E) Contents Page Foreword ..iv 1 Scope .1 2 Normative references ..1 3 Terms and definitions 4 Principle 5 Illumination for colour matching. ..2 5.1 General .2 5.2 Artificial illumination by means of a colour matching booth .2 6 Observer .2 7 Test panels and reference standards .3 7.1 General. .3 7.2 Reference standards .3 7.3 Preparation and coating. .3 7.4 Drying. 4 8 Procedure for colour comparison ..4 8.1 General 4 8.2 Colour comparison .4 9 Assessment of metamerism 10 Test report Annex A (normative) Colour difference rating scheme ..6 Annex B (informative) Metameric matches .7 Bibliography ..8 iii e=ZHEJIANG INST OF STANDARDIZATION C1 5956617 vided by IHS under lic vithout license from IHS