Spakon 6 Pcs Heat Sensitive Sheet Temperature Sensitive Sheet 6 Color Changing Heat Board, 24 to 34 Celsius Degree Transition for Science Experiment (10 x 10 Inch)

Got these and was disappointed because they would not change color. I set them aside planning on returning them. The next time I picked them up, they worked, just as they should. I use them one electronic circuit boards to find the hot spots. Example: When something fails after running for a while, it's probably a heat problem. These sheets will find the location of the heat. The part under the sheet is either defective, needs a fan or heat sink. Often aheat snk will solve the problem.

Save your money. These will barely react for 1-2 days out of the packaging and then they become useless. I bought them to add to my sensory wall in my classroom, total disappointment.

I like that they change color but dang it's a 6 inch by 6 inch sticker for almost 20$

Exactly what I expected, It's a thermal sheet like any other one. I use this to demonstrate heat transfer. Is it like the photos? NO, but if you ever owned somthing like this, then you wouldn't be surprised. Photos are definitely misleading, that is why I dropped it a star. Overall it works as intended.

Works great (on shiny side)!

They work, sort of. Just not the way the pictures make it look. In the demo photo, the handprint on the sheet looks almost as detailed as a hand under a thermal imaging camera. In reality, your hand on the sheet looks nothing like that. It's a single monocolor green, no detail to speak of. It's also kind of confusing, because the universal color for heat is red, but this thing shows heat as a greenish color. On top of that, you have to lay the sheet flat on a surface, ideally a cool one, to get the best heat signature, so it's finicky to use. I'm not a fan. They're expensive and nowhere near as useful as I thought they'd be. I bought them for product testing at my job, planning to use them in conjunction with the results I was getting under a thermal camera. But instead of confirming anything, this just added more confusion than anything else. So, 2 stars. They do technically react to heat, but between the misleading photos, the odd color scheme, and the fussy setup, they weren't worth the price. If you're expecting thermal-camera-level detail like the listing suggests, look elsewhere.

My child loved it.

My kids liked using this for a craft project and to play with as well. But the material isn’t that sensitive. We have to rub our hands together to make them hot enough to change the color and it quickly turns black after.