Cause
White toner tends to gather at the 1 mm width from the trailing edge of the white toner layer. As a result, 1 mm width from the trailing edge of the white toner layer appears as a white streak due to the insufficient fusing.
This is likely to occur if:
Printing an image in which white toner and CMYK toner overlap
Using a transparent film
Looking through the output transparent film
The image has dark density CMYK toner overlapped with white toner.
Trailing edge of a white toner layer overlaps CMYK toner.
