Question: My shower glass has the rope marks (streaks) in the glass running up and down. The issue shows up when the glass gets foggy after showering. What causes this effect?

Answer: Most likely the effect is coming from the tempering process when glass in contact with kevlar cords in the quenching section, especially by using the lower quality level of kevlar cords. Then the glass surface has small local differences and moisture behaves differently at different areas. It might be possible to remove by polishing/buffing glass surface. Or you may change to use Fortemp kevlar sleeves to cover the entire rollers instead of kevlar cords and it can solve the problem of rope mark completely.