# Joke shop vanishing ink **URL:** \ **Category:** Factual Questions\ **Created:** [June 8, 2018, 1:53pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678 "2018-06-08T13:53:21Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [June 8, 2018, 1:53pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/1 "2018-06-08T13:53:21Z")
When I was about six our family, for some reason, stopped at a joke shop. The owner of the shop contrived to drench my white shirt with some kind of “ink” that stained it blue. Dad thought it was hilarious but mom, probably because she did the laundry, was incensed. The guy had to reassure her that it would disappear by itself. Sure enough, over the next fifteen minutes or so while we were still in the store, the blue faded away leaving a damp spot where it had been, and a half hour later even the damp was gone, leaving no trace where it had been. Now, the blue was not a real deep blue, more like the azure the [Pilot Iroshizuku Kon-peki](https://www.jetpens.com/blog/blue-fountain-pen-ink-comparison/pt/387) on this pen seller’s site. Although the dampness took a while to evaporate, I recall it being colder than water evaporating would have been. Any ideas what the fluid might have been? ---
**Author:** ![Morgenstern](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@Morgenstern](https://boards.straightdope.com/u/Morgenstern)\ **Post date:** [June 8, 2018, 1:57pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/2 "2018-06-08T13:57:21Z")
Alcohol ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [June 8, 2018, 1:59pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/3 "2018-06-08T13:59:17Z")
> [@Morgenstern](#): > > Alcohol Blue alcohol? ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [June 8, 2018, 2:02pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/4 "2018-06-08T14:02:32Z")
It is a mix of mercury, powdered asbestos and radium. Standards were different then. You should probably have yourself checked. ([Alternately, it could have been a different mixture containing thymolphthalein and sodium hydroxide](https://www.stevespanglerscience.com/lab/experiments/vanishing-ink/).) ---
**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:** [June 8, 2018, 2:07pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/5 "2018-06-08T14:07:22Z")
Those mixtures don’t always disappear altogether. Sometimes you won’t notice until after you wash the clothing and you’ll notice discoloring. Maybe not as bad as when I was a kid and clothes weren’t as color fast as they are now. But I’d avoid spraying that on someone else’s clothes. ---
**Author:** ![Bert\_Nobbins](https://avatars.discourse-cdn.com/v4/letter/b/aeb1de/32.png) [@Bert\_Nobbins](https://boards.straightdope.com/u/Bert_Nobbins)\ **Post date:** [June 8, 2018, 4:22pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/6 "2018-06-08T16:22:38Z")
Thymolpthalein and sodium hydroxide sound like the true answer. But what would 3-Molar sodium hydroxide do to your shirt? I’d love to do some experiments, but in the current climate trying to obtain chemicals might be a short cut to orange pyjamas. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [June 8, 2018, 4:41pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/7 "2018-06-08T16:41:45Z")
> [@Bert\_Nobbins](#): > > Thymolpthalein and sodium hydroxide sound like the true answer. > > But what would 3-Molar sodium hydroxide do to your shirt? > > I’d love to do some experiments, but in the current climate trying to obtain chemicals might be a short cut to orange pyjamas. It isn’t 3 molar sodium hydroxide on your shirt–it is 10 ml of 3 molar sodium hydroxide diluted into 1,000 ml of water and ethyl alcohol. Big difference. Shouldn’t be any problem obtaining [the](https://www.amazon.com/Thymolphthalein-ACS-Pouch-Ricca-RDCT0450-5F1/dp/B009KSYHT8) [chemicals](https://www.amazon.com/Grade-Sodium-Hydroxide-Ounces-Batches/dp/B016AY7T76/ref=pd_lpo_vtph_lp_t_3?_encoding=UTF8&psc=1&refRID=3Y2RG9CVETATG1T9YCCN&dpID=51IyfKlWIWL&preST=_SX300_QL70_&dpSrc=detail). ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [June 8, 2018, 5:58pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/8 "2018-06-08T17:58:04Z")
Are you sure it wasn’t disappearing, reappearing ink? It worked for Roger Rabbit! ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [June 9, 2018, 5:18pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/9 "2018-06-09T17:18:53Z")
> [@Darren\_Garrison](#): > > It is a mix of mercury, powdered asbestos and radium. Standards were different then. You should probably have yourself checked. Thanks for the warning. That explains my third nipple. > [@](#): > > [Alternately, it could have been a different mixture containing thymolphthalein and sodium hydroxide](https://www.stevespanglerscience.com/lab/experiments/vanishing-ink/).) That’s it. The pic even looks pretty much like I did after the dousing. Part water and part ethanol would explain the coolness felt as well. Thanks? ---
**Author:** ![Ignotus](https://avatars.discourse-cdn.com/v4/letter/i/ecc23a/32.png) [@Ignotus](https://boards.straightdope.com/u/Ignotus)\ **Post date:** [June 9, 2018, 5:27pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/10 "2018-06-09T17:27:04Z")
> [@Bert\_Nobbins](#): > > But what would 3-Molar sodium hydroxide do to your shirt? I’d be more worried about what it would do to my _skin_! ---
**Author:** ![chappachula](https://avatars.discourse-cdn.com/v4/letter/c/d2c977/32.png) [@chappachula](https://boards.straightdope.com/u/chappachula)\ **Post date:** [June 10, 2018, 4:46am UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/11 "2018-06-10T04:46:35Z")
> [@Darren\_Garrison](#): > > Standards were different then… yeah, and not just the safety standards…standards of behavior were different too. Nowadays, marking up somebody else’s kid could probably get you sued, or arrested. ahh…the good ol’ days… [edit: Ooopss–just realized this is GQ. Sorry… I now return you to our regularly-scheduled thread] ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [June 10, 2018, 4:52am UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/12 "2018-06-10T04:52:15Z")
> [@chappachula](#): > > yeah, and not just the safety standards…standards of behavior were different too. > Nowadays, marking up somebody else’s kid could probably get you sued, or arrested. > ahh…the good ol’ days… > [edit: Ooopss–just realized this is GQ. Sorry… I now return you to our regularly-scheduled thread] The OP reminded me of the days when large department stores lost enormous amounts of business because employees would follow female shoppers around and spray them with perfume, often without asking them first. Yep, I remember the old invisible ink. ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [June 10, 2018, 12:21pm UTC](https://boards.straightdope.com/t/joke-shop-vanishing-ink/815678/13 "2018-06-10T12:21:24Z")
> [@nearwildheaven](#): > > The OP reminded me of the days when large department stores lost enormous amounts of business because employees would follow female shoppers around and spray them with perfume, often without asking them first. I did get asked once and I am no female. I had just entered the store when I was rapidly approached by someone in full-Goth brandishing one of those old-fashioned atomizers with the squeeze bulb on a tube. “Would you like to try Opium?” It was one of the few times in my life I did a full-blown recoil. “No!”