FS18.00
Revision II
Published on: 02/10/2026
Recommendations for index marks on pet bottle closures and neck finishes
Scope of application
This recommendation fact sheet provides the description of the different options when including index marks on closures and neck finishes, with the constraints and points to consider. The index marks considered are geometrically defined features, either positive (e.g., lugs) or negative (e.g., slots). These marks are intended to enable non-destructive application angle measurement. The measurement can be performed either manually by an operator or via automated vision systems (AVSs). Different types of inspection, and several types of the camera setups, in the case of AVS, might require different index marks.
Table of contents
1. Scope...................................................................................................................... 5
2. Introduction............................................................................................................. 5
3. Definitions............................................................................................................... 5
4. General considerations........................................................................................... 6
5. Camera configurations for automated inspection systems.................................... 6
6 Index mark on the closure...................................................................................... 8
6.1 Main recommendations................................................................................... 8
6.2 Best Before or other closure printing................................................................. 11
7 Index mark on the neck finish................................................................................... 11
7.1Main recommendations................................................................................. 11
2. Introduction............................................................................................................. 5
3. Definitions............................................................................................................... 5
4. General considerations........................................................................................... 6
5. Camera configurations for automated inspection systems.................................... 6
6 Index mark on the closure...................................................................................... 8
6.1 Main recommendations................................................................................... 8
6.2 Best Before or other closure printing................................................................. 11
7 Index mark on the neck finish................................................................................... 11
7.1Main recommendations................................................................................. 11
7.2 Positive index mark — round shape............................................................. 13
7.3 Negative index mark — round shape............................................................ 14
7.4 Positive index mark — rectangular shape.................................................... 15
7.5 Recommendations........................................................................................ 17
8 Precautions for detection...................................................................................... 17
9 Related documents............................................................................................... 18
10 Document history.................................................................................................. 18
7.3 Negative index mark — round shape............................................................ 14
7.4 Positive index mark — rectangular shape.................................................... 15
7.5 Recommendations........................................................................................ 17
8 Precautions for detection...................................................................................... 17
9 Related documents............................................................................................... 18
10 Document history.................................................................................................. 18
History
First edition: 02/2023
Second edition: 10/2026
First edition: 02/2023
Second edition: 10/2026
Contributors
ACQUA MINERALE SAN BENEDETTO,ACTEGA, ALPLA WERKE Alwin Lehner, AMCOR FLEXIBLES CAPSULES, AMCOR RIGID PACKAGING, APTAR GROUP, AROL S.p.A., ASTRA PLASTIQUE, BERICAP, BERLIN PACKAGING, BETAPACK, BRITVIC SOFT DRINKS, CAP SUSTAINABLE SOLUTIONS, COCA-COLA SERVICES, CORVAGLIA MOULD, DANONE EAUX FRANCE, DAVID ROSE PACKAGING SOLUTIONS, DAVID SYRETT PACKAGING CONSULTANCY Ltd, ECKES GRANINI, ETS ANDRE ZALKIN & CIE, GENOSSENSCHAFT DEUTSCHER BRUNNEN, HEINEKEN GLOBAL SUPPLY CHAIN, HEUFT, HUSKY INJECTION MOLDING SYSTEM, INTRAVIS GmbH, KRONES, LOGOPLASTE, LYONDELLBASELL INDUSTRIES - BASELL POLYOLEFINE, NESTLE WATERS MANAGEMENT & TECHNOLOGIES, NESTLÉ PRODUCT TECHNOLOGY CENTRE, NETSTAL Maschinen, OBRIST CLOSURES SWITZERLAND, OTTO HOFSTETTER, PEPSICO RUSSIA, PLASTISUD, REFRESCO FRANCE, RETAL LITHUANIA, SACMI IMOLA, SELIG FRANCE, SGT France, SIDEL BLOWING & SERVICES, SILGAN WHITE CAP MANUFACTURING, SIPA, SPA MONOPOLE, SUMITOMO (SHI) DEMAG PLASTICS MACHINERY, SUNTORY BEVERAGES & FOOD EUROPE, TORRENT INNOVA, TREFFPACK, UNITED CAP FRANCE, UNITED CAP WILZ, UNIVERSAL CLOSURE LIMITED, WISECAP GROUP, Z-MOULDS
Document under responsibility of working group:
PET plenary
WG chair: Alessandro FALZONI - SACMI IMOLA
This joint group is in charge of all GME data sheets ("Finish data sheets"), dedicated to the geometry of PET neck finishes and their related documents. These data sheets are related to finishes dedicated to the beverage industry (such as soft drinks, mineral water & wine), packaged in an aseptic environment and/or with nitrogen injection, and to the food industry (e.g. edible oils, vinegars, and sauces) and allowing to receive mainly plastic caps.
