# Where else was the tech that made T-shirts change colour used? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [August 9, 2020, 6:00pm UTC](https://boards.straightdope.com/t/where-else-was-the-tech-that-made-t-shirts-change-colour-used/917661 "2020-08-09T18:00:22Z")\ **Posts on this page:** 4\ **Page:** 2
**Author:** ![Paintcharge](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/paintcharge/32/7946_2.png) [@Paintcharge](https://boards.straightdope.com/u/Paintcharge)\ **Post date:** [August 11, 2020, 3:53pm UTC](https://boards.straightdope.com/t/where-else-was-the-tech-that-made-t-shirts-change-colour-used/917661/21 "2020-08-11T15:53:45Z")
[/quote] They’re still around and pretty popular- they’ve just become a LOT better than they used to be. Now they’re called “Transitions” lenses, and they go from clear to dark very quickly and vice-versa, especially in warmer weather. My kids have them, and they seem to be fantastic compared to what they used to be.[/quote] I got a pair of these fairly recently, and they didn’t work in the car. Something about polarized glass, IIRC. Very disappointing, as that is one of the few times that I actually want sunglasses. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [August 11, 2020, 3:55pm UTC](https://boards.straightdope.com/t/where-else-was-the-tech-that-made-t-shirts-change-colour-used/917661/22 "2020-08-11T15:55:04Z")
> [@CookingWithGas](#): > > I have a T-shirt that changes color in the sunlight, but it’s not from heat. I think it is activated by UV I have skin that works like that. ---
**Author:** ![k9bfriender](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k9bfriender/32/3283_2.png) [@k9bfriender](https://boards.straightdope.com/u/k9bfriender)\ **Post date:** [August 11, 2020, 5:02pm UTC](https://boards.straightdope.com/t/where-else-was-the-tech-that-made-t-shirts-change-colour-used/917661/23 "2020-08-11T17:02:31Z")
> [@Paintcharge](#): > > I got a pair of these fairly recently, and they didn’t work in the car. Something about polarized glass, IIRC. Very disappointing, as that is one of the few times that I actually want sunglasses. UV light. It’s what makes them change, and it is blocked by most glass. And I agree, that’s what turned me off of them in the first place, as it is while driving that I _need_ to wear sunglasses. Preferably polarized, which I don’t think that Transitions offered either. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [August 11, 2020, 7:49pm UTC](https://boards.straightdope.com/t/where-else-was-the-tech-that-made-t-shirts-change-colour-used/917661/24 "2020-08-11T19:49:54Z")
as others have pointed out, color-changing that rely on temperature change are in a lot of consumer goods, most notably those temperature-changing mugs. But you still see plastic cups that incorporate thermal color changing chemicals in them. And the people who chose UV-activated color change are correct. You can still get shirts that use this technology. Not to mention fabrics, threads, color-changing beads, and other items. It is, indeed, activated by long-wave ultraviolet, but the change is more rapid and noticeable with shorter wave light. I have a string of such UV beads hanging here in my cubicle. They will change color when sunlight passing through the window, but the color change is greater and faster if I take it outside. There are a LOT of photochromic chemicals, and the response spectrum varies. Mercury dithizonate changes from orange to blue under direct sunlight, but not very much when filtered through glass. If you mix it with clear nailpolish you can make photochromic paint. [Previous page](https://boards.straightdope.com/t/where-else-was-the-tech-that-made-t-shirts-change-colour-used/917661.md?page=1)