The classification of printing defects may vary depending on the standard or criteria used by each company or industry. However, some common categories of can printing defects can be identified:

1. Grease: Presence of any type and amount of grease on the outside of the printing sheets.
2. Out-of-size printing: Incorrect dimensions of the print that seriously affect the appearance of the processed material or hinder its correct processing.
3. Defective reserves: Reserves, generally of smaller width than specified, which hinder the correct transformation of the material or affect its good visual appearance.
4. Shade difference with the color gamut: Appreciable difference between the shade of the print run and the color gamut approved by the customer.
5. Defective UPC code: Anomalies detected in the printed UPC code that may affect its correct reading.
6. Metal exposure: Presence of areas where the metal of the can shows through due to a defect in the printing.
7. Hardness test: Failures in the hardness of the printed ink, which may affect its strength and durability.
8. Sterilization resistance: Problems related to the ability of the print to withstand sterilization processes.

It is important to note that this classification may not be exhaustive and that each company may have its own categories and classification criteria for printing defects on cans.

how the hardness of the tinplate influences the drawing process Main defects of a 2pc aluminum can The Influence of Physicochemical Parameters on Can Defects: A Statistical Approach Common defects in twist-off caps and solutions for their prevention Aluminum Can Decorator Defects: Causes, Effects and Solutions GMG PRESENT IN COLOR22 New functions and possibilities for coating and print inspection systems QA OF LITHOGRAPHIC MATERIALS SUPERFICIAL DEFECTS OF THE TIN