I noticed a few years ago that a lot of car windows had a sort of honeycomb image on the passenger windows. It didn’t matter what you did, there was no getting rid of it. I assume it was a flaw caused by manufacturing technique in trying to achieve some benefit.
Anyone know what caused it? Why there wasn’t a recall? (Probably because it was cosmetic only and way too expensive?)
The only time I’ve seen a pattern on car glass is when I’m wearing polarized sunglasses. I assume it’s a result of the process of making the safety or tempered glass.
It’s psychological–a marketing gimmick. It began as gas prices began driving sales of smaller cars. As people adjusted and the market started to shift back towards larger cars, the sluggish compact car sales needed something to help out. So they went with a subtle honeycomb patter on the windows, because honeycomb big; yeah yeah yeah…
I’ve never noticed any honeycomb pattern, though I have noticed the pattern that you see through polarized sunglasses that Turek mentioned (I’d call it a checkerboard instead of a honeycomb, but it may be what the OP is talking about).
If it’s bright enough out you can see it even without polarized glasses. I thought it was intentionally manufactured that way to reduce glare, but it may just be an artifact of the production of safety glass due to the way it is layered and stretched during manufacturing. Anyone know for sure?
“Heat-strengthened or fully –tempered glass that is manufactured in a horizontal tempering furnace may contain slight surface waves caused by contact with the rollers. This waviness or roller distortion can be detected when viewing reflected images from a distance. Orientation of the glass in the furnace is critical in order to minimize the appearance of the roll wave distortion. It is recommended that the roller wave be oriented parallel to the horizontal glass dimension.” http://www.aisglass.com/flat_tempered.asp
This, except I don’t think it has to do with the safety glass. I think some cars have some type of coating on them. The rear windows of my Jag show this pattern, but not the windshield. The windows don’t look tinted, but I wouldn’t be surprised if there is not some kind of UV coating.