Humi-Smart Humidity Indicator Cards

[MindSoup]

I'm sure most of us have heard of boveda packs, well there is another brand called Humi-Smart, alongside their humidity packs they also make humidity indicator cards, they change colour to indicate a set humidity as a way of showing your humidity pack has run its course.

 

I don't really feel the need for the packs themselves as I use good quality jars and my humidity stays pretty stable, however the indicator cards got me interested as they're a lot cheaper than mini hygrometers and they don't require batteries, so could be perfect for the begining stage of being in the jar, to let me know if I need to keep Burping and to keep in "work" jars to let me know it its getting a bit too dry. 

 

Has anyone used these before? Are they reliable? Do they have good longevity? Have I got a good understanding off their function and will they work for my intended purpose?

Edited January 7, 2021 by MindSoup