The development of visual defects, such as bubbles, local delamination, cloudiness and discoloration in laminated glass are unwanted phenomena that negatively affect the visual quality of a laminate but do not affect its structural safety. These defects can arise due to numerous influences during the production of a laminate and/or can be triggered during its lifetime. To get a better understanding of the defect formations, several laminated glass specimens were deliberately produced erroneously to promote these unwanted phenomena. Subsequently, the specimens were subjected to durability tests such that the link between a production fault, a triggering mechanism and the resulting defect pattern could be investigated. The tests are conducted on laminates with a PVB interlayer.