Chip repairs are most triumphant while smaller than a quarter and no longer within the driver’s direct line of sight
https://mike-wiki.win/index.php/28802_Asheville_Auto_Glass_Repair:_Rear_Glass_Repair_Guide
Chip repairs are so much a success while smaller than 1 / 4 and no longer in the driving force’s direct line of sight, maintaining readability and safety for this reason.