Dry & Dry Premium Humidity Indicator Cards (12 Cards) - 10-60% 6 Spot(Reusable)

I put these primarily in containers holding moisture sensitive materials, but I also stick them on the shelf in my work shop to keep tabs on the room humidity. Simple to use and last a really long time.

Etwas schlecht zu erkennen der Farbwechsel.

I have a host of 3D filament spools and like to store them all in dry storage boxes, some are used infrequently and I'll store unopened spools as well. I bought the cheap $2 humidity sensors but they won't register below 20% and can't be used for really dry environments. These moisture indicating strips are cheaper and more accurate. They are really designed for dry storage measurements. The only downside is they are hard to read and it takes some "practice" to translate the lavender color to moisture value. I initially used a lab grade sensor as a reference and added it to some boxes with a strip to help me understand the color shift. I'm used to seeing the mostly blue dots and can pretty easily tell when the desiccant needs to be recharged. These are much better at monitoring dry storage than the cheapo humidity gages and I highly recommend.

Using these for 3D printer filter in vacuum bags and they work really well. Take a little while to colour change to ambient humidity but they are a great option to check on humidity in long term storage

I understood this product to be able to change colour back multiple times. However when I removed it from its packaging all dots turned pink and never returned back to blue again.