tag:blogger.com,1999:blog-4459310030661835522.post521715726429286469..comments2024-03-28T02:28:16.845-05:00Comments on Jenny's Crayon Collection: Crayola Changeable Crayons: What's Inside the BoxJenny Crowtherhttp://www.blogger.com/profile/10581935202650222384noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-4459310030661835522.post-39321003508282023682021-03-03T18:59:13.049-06:002021-03-03T18:59:13.049-06:00I was trying to find out if they still made these....I was trying to find out if they still made these. I had them when I was little. According to the google patent search, it's probably US5460647A. The patent mentions leuco dye which is a thermochroic dye. The patent mentions the idea of the dye changing color when the acid in the second is applied. Sadly I haven't been able to find anyone making a similar product.Kithttps://www.blogger.com/profile/05818297267957935857noreply@blogger.com