ISO INTERNATIONAL STANDARD 8791-4 Third edition 2021-05 Paper and board Determination of roughness/smoothness (air leak methods) Part 4: Print-surf method Papier et carton - Détermination de la rugosité/du lisse (méthodes du débit d'air) - Partie 4: Méthode Print-surf Reference number IS0 8791-4:2021(E) OST @ IS0 2021 IS0 8791-4:2021(E) COPYRIGHT PROTECTED DOCUMENT @ IS0 2021 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting below orIso's memberbodyin the country ofthe requester ISO copyright office CP 401 · Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 0111 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2021 - All rights reserved