# Border of Black Dots on Windshield

**URL:** <https://boards.straightdope.com/t/border-of-black-dots-on-windshield/509711>\
**Category:** Factual Questions\
**Created:** [September 11, 2009, 6:33pm UTC](https://boards.straightdope.com/t/border-of-black-dots-on-windshield/509711 "2009-09-11T18:33:05Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![calmondo](https://avatars.discourse-cdn.com/v4/letter/c/e56c9b/32.png) [@calmondo](https://boards.straightdope.com/u/calmondo)\
**Post date:** [September 11, 2009, 6:33pm UTC](https://boards.straightdope.com/t/border-of-black-dots-on-windshield/509711/1 "2009-09-11T18:33:05Z")

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Most, if not all, recently manufactured automobiles have a border of black dots on the windshield. The dot pattern varies in width from ½ inch to slightly more. In the location of the rear view mirror, the pattern becomes wider. The rear windows often has these dots.

What is the purpose for these dots?

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**Author:** ![JerseyFrank](https://avatars.discourse-cdn.com/v4/letter/j/bcef8e/32.png) [@JerseyFrank](https://boards.straightdope.com/u/JerseyFrank)\
**Post date:** [September 11, 2009, 6:40pm UTC](https://boards.straightdope.com/t/border-of-black-dots-on-windshield/509711/2 "2009-09-11T18:40:58Z")

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I always assumed it was the radio antenna.

[This site](http://www.wonderquest.com/windshield-dots.htm) says it’s something for an adhesive to grip. Others say it’s only for additional shading.

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**Author:** ![Sigene](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@Sigene](https://boards.straightdope.com/u/Sigene)\
**Post date:** [September 12, 2009, 12:01am UTC](https://boards.straightdope.com/t/border-of-black-dots-on-windshield/509711/3 "2009-09-12T00:01:39Z")

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I had a similar thread about a year ago. somewhere in the archives. I think the consensus was that is was for shading and it was called “frit”. My question was slightly different in that my 08 toyota has an asymmetrical pattern (Frit on the right but not on the left)

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**Author:** ![cornflakes](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@cornflakes](https://boards.straightdope.com/u/cornflakes)\
**Post date:** [September 12, 2009, 3:10am UTC](https://boards.straightdope.com/t/border-of-black-dots-on-windshield/509711/4 "2009-09-12T03:10:36Z")

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Shading. It also a decorative touch for the black area that covers the windshield adhesive and the rear mirror mount.

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**Author:** ![cerberus](https://avatars.discourse-cdn.com/v4/letter/c/71e660/32.png) [@cerberus](https://boards.straightdope.com/u/cerberus)\
**Post date:** [September 12, 2009, 3:18am UTC](https://boards.straightdope.com/t/border-of-black-dots-on-windshield/509711/5 "2009-09-12T03:18:01Z")

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My car has a block of dots above the rear view mirror, presumably to protect the electronics from excessive heat.

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**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\
**Post date:** [September 12, 2009, 4:07am UTC](https://boards.straightdope.com/t/border-of-black-dots-on-windshield/509711/6 "2009-09-12T04:07:48Z")

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> [@cerberus](#):
>
> My car has a block of dots above the rear view mirror, presumably to protect the electronics from excessive heat.

Not really. Your sun visors don’t really cover over the rear view mirror area. Driving toward or almost toward the sun can cause blinding light to come in just slightly above the rear view mirror if conditions are just right.  
By putting black shading in front of the mirror, this is prevented.  
Strictly a driver / passenger comfort issue.