New construction window scratching is a common problem. Common contributors are surface contaminates such as stucco, dirt (most dirt contains sand) and concrete. Window experts at Read Consulting often are asked to examine scratched windows and determine the cause of scratches. These windows were not scratched. Microscopic examination of the streaked portions of a representative window revealed the presence of stuck on glass particles that aligned in a linear pattern. These particles were baked on during the glass tempering process.
It is impossible to remove these glass particles with a metal probe.