DRAFT UGANDA STANDARD  
  DUS 2242  
First  Edition  
2020 -mm-dd 
 
 
 Reference number  
DUS 2242: 2020  
© UNBS 2020   
  
Envelope  — Specification  
 DUS 2242 : 2020  
ii © UNBS 2020  – 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 application  
© UNBS 2020   
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 from 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 4 333 2 50/1/2/3  
Fax: +256 41 4 286 123  
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  DUS 2242:2020  
© UNBS 2020  – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 Requirements  ................................ ................................ ................................ ................................ .........  1 
4.1 General  ................................ ................................ ................................ ................................ ...................  1 
4.2  Construction  ................................ ................................ ................................ ................................ .........  2 
4.2.1  Open End envelopes  ................................ ................................ ................................ .............................  2 
4.2.2  Open Side envelopes  ................................ ................................ ................................ ............................  2 
4.3  Designation  ................................ ................................ ................................ ................................ ...........  2 
4.4  Size................................ ................................ ................................ ................................ .........................  2 
4.4.1  Dimensions of Envelopes  ................................ ................................ ................................ .....................  2 
4.4.2  Dimensions of Windows  ................................ ................................ ................................ .......................  2 
4.4.3  Tolerances  ................................ ................................ ................................ ................................ ..............  3 
4.5  Printing  ................................ ................................ ................................ ................................ ..................  5 
4.6  Materials  ................................ ................................ ................................ ................................ ................  5 
4.6.1   Paper  ................................ ................................ ................................ ................................ ......................  5 
4.6.2  Window Material  ................................ ................................ ................................ ................................ .... 5 
4.6.3   Joints (seams)  ................................ ................................ ................................ ................................ ...... 5 
4.6.4   Flaps  ................................ ................................ ................................ ................................ ......................  6 
5  Packaging and Labelling  ................................ ................................ ................................ .....................  6 
5.1  Packaging  ................................ ................................ ................................ ................................ ..............  6 
5.2 Labelling  ................................ ................................ ................................ ................................ .................  6 
6 Sampling and criteria for conformity  ................................ ................................ ................................ .. 6 
6.1 Lot ................................ ................................ ................................ ................................ ...........................  6 
6.2 General Requirements for Sampling  ................................ ................................ ................................ ... 6 
6.3 Criteria for Conformity  ................................ ................................ ................................ ..........................  7 
Annex  A (informative)  Envelope Construction Designs  ................................ ................................ ...............  8 
Bibliography  ................................ ................................ ................................ ................................ ........................  9 
 DUS 2242 : 2020  
iv © UNBS 2020  – All rights reserved  
 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 co -
ordinate the elaboration of  standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(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 World 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 recommending 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/ SC 3,  Paper and paper 
products   
  
© UNBS 2020  – All rights reserved  1 
 Envelope  — Specification  
1 Scope   
This Draft Uganda standard specifies  the designations, requirements , test  methods  and sampling of 
envelopes  made of paper .  
lt does not contain any specification as to the ways of closing them . 
2 Normative references   
The following referenced documents are referred to in the text in  such a way that some or 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 187 , Paper, board and pulps — Standard atmosphere for conditioning and testing and procedure for 
monitoring the atmosphere and conditioning of samples  
ISO 2758 , Paper — Determination of bursting strength 58:20 
US ISO 536, Paper and board — Determination of gra mmage  
US ISO 1923 , Cellular plastics and rubbers — Determination of linear dimensions  
US ISO 1974, Paper — Determination of tearing resistance — Elmendorf method  
3 Terms and definitions   
For the purposes of this document, the following terms and definitio ns apply.  
3.1  
flap 
fold-in of an envelope so as to close it  
3.2  
seam 
central point running parallel to the height of the open end envelope. It may be in the centre or the side.  
3.3  
window  
opening in the envelope with or without a translucent patch desi gned to allow the contents inside the envelope 
to show through  
4 Requirements  
4.1 General  
4.1.1  The envelope shall be a flat case, generally rectangular , except square envelopes , and made from 
one sheet of paper.   
2 © UNBS 2020  – All rights reserved  
 4.1.2  The paper shall be so folded a s to pr ovide a plain front and  back consisting of four overlapping flaps. 
Three flaps shall be stuck together and completely sealed while the fourth, which may or may not be gummed, 
serves as a closure  (or sealing flap ). The left and right side flaps shall be sea led under the bottom flap.  
4.1.3  In case the fourth flap is gummed, the adhesive used for this purpose shall be re -moistenable, 
nonhygroscopic, non -toxic and of vegetable or synthetic type. Animal glue shall not be used for this purpose.  
4.1.4 The front o r working side may have a window fitted wit h transparent material  
4.1.5 The overlay between envelope and envelope window shall be glued carefully and completely  to the  
inner side of the envelope and shall be located outside the reserved area for bar codin g. 
4.1.6  The lowest part of the address side of the envelope, 20 mm wide, covering the whole length of the 
envelope shall be reserved for bar coding.  
4.1.7  The inner portion of the envelope may be tinted, if desired by the purchaser; design and shade of 
tint shall be as agreed to between the purchaser and the supplier.  
4.2  Construction  
Envelopes shall be manufactured from either open side or open end construction designs.  Both these design s 
may be with or without windows  
NOTE  — Envelopes can be manufact ured in an almost endless number of sizes and shapes. Dozens of different designs 
can be developed from these two basic styles to meet the customer’s particular requirements.  
4.2.1  Open E nd envelopes  
Open E nd envelopes have their opening and the seal flap located on the short dimension. They are well 
suited  to hand insertion applications . Open End envelopes are also known as “Pocket envelopes” and l arger 
Open End envelopes are also called “Catalogs”. (See Annex A)  
4.2.2  Open Side envelopes  
Open Side envelop es are ideal for automatic insertion applications and are suited for hand insertion 
applications as well. Open Side envelopes are also known as “Banker envelopes” and larger  Open Side 
envelopes are also called “Booklets”.  (See Annex A)  
4.3  Designation  
Envelopes shall be designated by a reference to the construction design  followed by an indication of size. The 
size shall be expressed by its two dimensions in millimetres, the smaller dimension being given first:  
EXAMPLE  Open End  envelope, 229 × 324  
4.4  Size 
4.4.1  Dimensions of Envelopes  
The nominal dimensions of envelopes , as measured in accordance with US ISO 1923,  shall be as given in 
Table 1. The size of the envelopes shall be expressed by its two dimensions in millimetres, the smaller 
dimension being giv en first.  
4.4.2  Dimensions of Windows  
For an envelope with a window, the nominal dimensions of the window shall be 39 mm × 93 mm, the distance 
of the left edge of the window from the left edge of envelope shall be 20 mm and the distance of the lower 
edge o f the window from the bottom of the envelope shall be 20 mm.  DUS 2242 : 2020  
© UNBS 2020  – All rights reserved  3 
 4.4.3  Tolerances  
The tolerance on all nominal dimensions given in Table 1 shall be ±5 mm. 
  
© UNBS 2020  – All rights reserved  4 
 Table 1  — Envelope dimensions  
Envelope Style  Size 
(mm)  
Commercial  89 × 152  92 × 165  92 × 219  95  × 171  98 × 190 98 × 225  105 × 241  110 × 220 110 × 230 114  × 241  176  × 254  
178  × 254  229  × 324  254  × 381  305  × 405         
Baronial  92  × 130  111 × 146  133 × 184  212 × 165         
A style  98 × 225  111 × 146  121 × 165  133 × 184  152 × 241  206 × 410       
Square  127 × 127  140 × 140  152 × 152  165 × 165  178 × 178  190 × 190  203 × 203  216 × 216  229 × 229  214 × 241  343 × 343  
Booklet  121 × 165  140 × 191  140 × 206  146 × 225  152 × 229  152 × 241  165 × 241  178 × 254  191 × 267  222 × 292  229 × 305  
Catalog  98 × 191  102 × 162 117 × 171 127 × 191 140 × 191 140 × 210 105 × 241 114 × 264 121 × 279 127 × 292 152 × 229 
165 × 241 178 × 254 191 × 267 210 × 286 216 × 267 222 × 286 229 × 305 241 × 318 254 × 305 254 × 330 292 × 368 
Wallet Flap  105 × 241  114 × 264  121 × 279  127 × 292  152 × 305        
Mail 105 × 241  229 × 305 241 ×318  254 × 330        
 
  
© UNBS 2020  – All rights reserved  5 
 4.5  Printing  
The envelopes, if required, may be suitably and  distinctly printed as agreed upon  between the purchaser and 
the supplier. This printing shall be on the smooth surf ace of the paper and at least 2.0 cm away from any of 
the edges.  
4.6  Materials  
4.6.1  Paper  
4.6.1.1 The grammage of the paper used shall be dependent on the area of the envelope and it shall be 
as per Table 1 when tested in accordance with US ISO 536.  A tolerance of ± 5 percent  shall be permitted on 
the nominal grammage for individual test results  and the mean of 10 test results shall not vary from nominal 
grammage by more than ± 2.5 percent.  
4.6.1.2  The surface of the paper shall be of uniform structure , free from dust/ dirt, blemishes, creases, 
specks and holes. Mineral filling shall not cause corrosive or abrasive damage to transport means.  
4.6.1.3  The paper shall be dimensionally stable and flat when kept in ambient conditions of 20 -80 
percent relati ve humidity and 15 to 35°C temperature.  
4.6.1.4  The paper shall also comply with t he requirements given in Table 1 . 
4.6.2 Window Material  
4.6.2.1 At a minimum, windows shall be placed  12.7 mm  from the side and the bottom of the face of the 
envelope to ens ure adequate room for patch adhesive.  
4.6.2.2 Transparency shall be adequate to ensure proper legibility to text under the window with normal 
sight.  
4.6.2.3 Glassine paper with a minimum grammage of 35 g/m2, cellophane paper of minimum grammage 
40 g/m2 or PVC/BOPP of  a minimum thickness of 15  micron s shall be used as window material. The material 
shall stick firmly without any wrinkles to the inner side of plain front of the envelope.  
Table 2 —  Requirements  of Paper  for making envelopes  
Parameter  Area of e nvelope  
( × 103 mm2) Requirement  Test Method  
 
Grammage  
 (g/m2), Nominal  Up to 30  70  
US ISO 536  31 to 80  90 
81 to 120  120 
121 and above  140 
Burst Index, Nm2/g (min)   2.0 ISO 2758  
Tear index (Machine 
Direction) mNm2g, min.   12.0 US ISO 1974  
 
4.6.3  Joints  (seams)  
4.6.3.1 The pasting of the joints, wherever required, shall be even and continuous without leaving any 
gap or opening.  
4.6.3.2 The gum applied on the sealing flap, seam and bottom flap shall not extend beyond the 
overlapping portion. T he left and right side flaps shall be sealed under the bottom flap.   
6 © UNBS 2020  – All rights reserved  
 4.6.3.3 The width of the bottom flap and the seam shall be between 1.5 cm and 2.5 cm to ensure the 
strength of the envelope and the safety of its contents.  
4.6.4  Flaps  
4.6.4.1 The flaps f or closing the envelopes shall be of suitable shape, as agreed to between the 
purchaser and the supplier.  
4.6.4.2 Their width shall be such that it closes the envelope securely and ensures the safety of its 
content.  
NOTE — The adhesive applied on the seali ng flap should not go beyond the overlapping area so that it should not stick to 
the letter  in the envelope  
5  Packaging and  Labelling  
5.1  Pack aging  
Envelopes shall be packaged in suitable packaging materials which shall protect the product from damage 
during transportation, handling and storage.  
5.2 Labelling  
Each package shall be labelled  with the following information:  
a) name and address of manufacturer ; 
b) size and colour of the envelope ; 
c) batch/lot number ; 
d) number of envelopes in the package ; 
e) whether gummed or ungummed;  and 
f) country of origin  
6 Sampling and criteria for conformity  
6.1 Lot 
All the packages of  envelopes of identical size and belonging to the same batch of manufacture shall be 
grouped together to constitute a lot.  Each lot shall be tested separat ely for various requirements of this 
specification.  
6.2 General Requirements for Sampling  
6.2.1 Samples shall be protected from exposure to heat, direct sunlight, liquids, varying humidity conditions 
as well as any other harmful influences.  
6.2.2  Samples s hall be handled as little as possible and contact with sweated hands shall be strictly  
avoided.  
6.2.2 The number of envelopes to be sampled  from each lot shall be as given in Table 3 . DUS 2242 : 2020  
© UNBS 2020  – All rights reserved  7 
 6.3 Criteria for Conformity  
6.3.1 While conducting the tests for paper quality, no failure shall occur for the lot to be accepted as 
conforming to this specification.  
Table 3 — Scale of sampling  
 
Lot size (Number of envelopes)  Sample size  
Up to 100  5 
101 to 150  8 
151 to 300  13 
301 to 500  20 
501 to 1 000  32 
1 001 to 3 00 0 50 
3 001 to 10 000  80 
10 001 and above  125 
 
  
8 © UNBS 2020  – All rights reserved  
 Annex  A 
(informative)  
 
Envelope Construction Designs  
 
 
 DUS 2242 : 2020  
© UNBS 2020  – All rights reserved  9 
 Bibliography  
[1] IS 13892 (1999): Correspondence envelopes — Specification   
[2] A complete Referenc e Guide to Envelope Construction, Size and Conversion , [viewed 2020 -01-16]. 
Available at http://cmykprinting.com/resource -center/reference  
 DUS 2242:2020  
© UNBS 2020  – All rights reserved  11 
 Certification marking  
Products that conform to Uganda standards may be marked with Uganda National Bureau of Standa rds 
(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 operate d by 
the Uganda National Bureau of Standards and in conjunction 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 syste m 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 c onditions of licensing may be obtained from the Director, Uganda 
National Bureau of Standards.  
 
 DUS 2242:2020    
 
ICS 85.080.10  
Price b ased on nn pages  
© UNBS 2020 – All rights reserved