An irreversible humidity indicator card comprising an intermediate carrier
member containing one or more holes, a clear, water vapor permeable first
outer layer secured to the first side of the carrier member, a
deliquescent material contained within the holes in the carrier member, a
dark colored, absorbent sheet material secured to the back side of the
carrier member to cover the holes in the carrier member and a second outer
layer which covers the colored absorbent sheet material and a portion or
all of the back side of the intermediate carrier member.
