Most upvoted comment
My visitor badge expired as the day went on(r/mildlyinteresting)
So how does this work?
The best explanation i can find for now is this:
>Each TIMEbadge consists of a specially coated white adhesive FRONTpart and a BACKpart that is pre-printed with time-release ink. Once the FRONTpart is applied to the BACKpart, the TIMEbadge is activated. The result is a gradual color change that signals expiration when completed.
From here , if you see the image in page 4 of this .pdf the above explanation makes sense.
I know it doesn’t explain the process. so i am looking up more stuff.
In the mean time if you want to buy these you can do so from amazon
EDIT:
tldr , not quite explains the whole process but still…..
The way i understand is there are two parts to the badge one front part and one back part, the back part has some chemicals which have the property that they can dissolve front part substance and seep up to the front of the front part, which is a plastic like opaque white surface with some info about the visitor written on it.so as time progresses the ink seeps up to front part and becomes visible as “void” or whatever way they were designed to.
I know the explanation is shabby, but am i right?