DRAFT UGANDA STANDARD  
  DUS 435  
Second  Edition  
2021 -mm-dd 
 
 
 Reference number  
DUS 435 : 202 1 
© UNBS 202 1  
  
Duplicating paper  — Specification  
 
 
 
 DUS 435: 2021 
ii © UNBS 2021 – All rights reserved  
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct app lication  
© UNBS 2021  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, including photocopying and microfilm, without prior written 
permission f rom UNBS.  
Requests for permission to reproduce this document should be addressed to  
The Executive Director  
Uganda National Bureau of Standards  
P.O. Box 6329  
Kampala  
Uganda  
Tel: +256 41 7 333 2 50/1/2 
Fax: +256 41 4 286 123  
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  
 
 DUS 435 :2021 
© UNBS 202 1 – All rights reserved  iii 
 Foreword  
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade , Industry and 
Cooperatives established under Cap 327 , of the Laws of Uganda , as amended .  UNBS is mandated to c o-
ordinate the elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) ;  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards ; and  
(c) the National Enquiry Point on TBT  Agreement  of the Worl d Trade Organisation (WTO).  
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of key stakeholders 
including government, academia, consumer groups, private sector and other interested parties.  
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommen ding the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
The committee responsible for this document is Technical Committee UNBS /TC 7, Textiles, leather, paper 
and related products , Subcommittee SC 3, Paper and paper  products . 
This second edition cancels and replaces the first  edition (US 435:2003), which has been technically revised 
The main changes compared to the previous edition are as follows:  
— the clause for normative references has been added.  
— Inclusion of Table 1  to give the different duplicating paper sizes  
— Inclusion of test methods in the table indicating the p hysical and optical properties for duplicating papers  
 DRAFT UGANDA STANDARD  DUS 435 : 202 1 
 
© UNBS 2021  – All rights reserved  1 
 Duplicating paper  — Specification  
1 Scope   
This Draft Uganda Standard specifi es the requirements for duplicating papers. The standard applies to 
duplicating papers for stencil duplicators using emulsion or oil based inks paragraph.  
2 Normative references   
The following documents are referred to in the text in such a way that some o r all of their content constitutes 
requirements of this document. For dated references, only the edition cited applies. For undated references, 
the latest edition of the referenced document (including any amendments) applies.  
ISO 5636 -3, Paper and board — Determination of air permeance (medium range) — Part 3: Bendtsen method  
ISO 8791 -2, Paper and board — Determination of roughness/smoothness (air leak methods) — Part 2: 
Bendtsen method  
US ISO 187, Paper, board and pulps — Standard atmosphere for conditioni ng and testing and procedure for 
monitoring the atmosphere and conditioning of samples  
US ISO 536, Paper and board — Determination of grammage  
US ISO 2470 -1, Paper, board and pulps — Measurement of diffuse blue reflectance factor — Part 1: Indoor 
daylight conditions (ISO brightness)  
US ISO 2471, Paper and board — Determination of opacity (paper backing) — Diffuse reflectance method  
3 Terms and definitions   
For the purposes of this document, the following terms and definitions apply.  
ISO and IEC maintain te rminological databases for use in standardization at the following addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp  
2.1  
duplicating paper  
absorbent or semi -absorbent paper, unsized or slack -sized, with a matt finish, used f or making copies from a 
stencil duplicating machine  
2.2  
chemical wood pulp  
wood reduced to pulp by a chemical process, for example, sulphite or sulphate, which eliminate the greater 
part of the non -fibrous components  DUS 435 : 2021  
2 © UNBS 2021  – All rights reserved  
 2.3  
mechanical pulp  
pulp obtained  from wood entirely by mechanical means, for example, by the action of a grindstone or refiner   
4 Requirements  
4.1 General  
4.1.1  Composition  
The paper shall be composed of bleached chemical wood pulp and/or mechanical pulp.  
4.1.2  Sizing  
The paper shall be  engine sized.  
4.1.3  Uniformity  
The paper shall be of uniform formation, thickness and substance, and shall be evenly finished, free from 
specks, holes and other blemishes.  
4.1.4  Cutting  
The paper shall be cut square, with clean edges, by guillotine or oth er effective means, and with the machine 
direction consistent with the longer measurement.  
4.1.5  Sizes 
4.1.5.1  The paper shall be manufactured according to the sizes indicated in Table 1. These 
measurements shall be taken with the aid of a metre rule under  a standard testing atmosphere specified in 
ISO 187  
4.1.5.2  The permitted size tolerance shall be ± 2 mm  
Table 1 — Duplicating paper sizes  
Designation  Dimensions  
mm 
4A0 1 682  × 2 378  
2A0 1 189  × 1 682  
A0 841 × 1 189  
A1 594 × 841 
A2 420 × 594 
A3 297 × 420 
A4 210 × 297 
F/S 203 × 330  
A5 148 × 210 
A6 105 × 148 
A7 74 × 105 DUS  435: 202 1 
© UNBS 2021 – All rights reserved  3 
 A8 52 × 74 
A9 37 × 52 
A10 26 × 37 
 
4.2 Performance requirements  
4.2.1  The paper shall allow the production of duplicated copies free from set -off and excessive print -
through.  
4.2.2  There shall be no feathering when using duplicating ink  
4.3 Physical and optical requirements  
The paper shall comply with the physical and optical r equirements specified in Table 2  below, when tested 
according to the  test methods specified therein . 
Table 2  — Physical and optical properties for duplicating papers  
Characteristic  Requirement  Test method  
Type  A Type  B 
Grammage, g/m2 ±5% 70 80 US ISO 536  
Roughness, ml/min,  
max.  700 700 ISO 8791 -2 
Porosity, ml/min,  max.   1 200  1 200  ISO 5636 -3 
Opacit y, % Min . 88 88 US ISO 2471  
Brightness, % mi n. (for 
white paper only)  72 72 US 2470 -1 
4 Packaging  
The paper shall be delivered flat and correctly put up in packets. The packets shall be well wrapped with firmly 
secured ends, and be capable of withstandi ng multiple handling.  
5 Labelling  
Each packet shall be clearly labelled  with the following information:  
a) description of the paper , that is duplicating paper ; 
b) grammage ; 
c) dimensions  of the duplicating papers ; 
d) colour of the paper;  
e) number of sheets  in the packet ; and  
f) name of the manufacturer or importer or supplier, or registered trade mark.  
 DUS  435: 202 1 
© UNBS 2021  – All rights reserved  5 
 Certification marking  
Products that conform to Uganda standards may be marked with Uganda National Bureau of Standards 
(UNBS) Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is governed by the Standards Act, and the Regulations made 
thereunder. This mark can be used only by those licensed under the certification mark scheme operated by 
the Uganda National Bureau of Standards and in conju nction with the relevant Uganda Standard. The 
presence of this mark on a product or in relation to a product is an assurance that the goods comply with the 
requirements of that standard under a system of supervision, control and testing in accordance with the 
certification mark scheme of the Uganda National Bureau of Standards. UNBS marked products are 
continually checked by UNBS for conformity to that standard.  
Further particulars of the terms and conditions of licensing may be obtained from the Director,  Uganda 
National Bureau of Standards.  
 
 DUS 435 : 202 1   
 
ICS 85.080.10  
Price based on nn pages  
© UNBS 2021– All rights reserved