Patent ID: 8754006

Claim:
A packaging material comprising a colored element which at about 38° C. discolors partially, revealing a marking, wherein: (a) the colored element comprises a first portion, which forms the marking printed with a conventional ink, and a second portion printed with a thermochromic ink; (b) the thermochromic ink is colored below about 38° C. and becomes colorless when 38° C. is reached or exceeded; (c) the first portion and second portion are arranged so that the first portion is invisible below about 38° C., but becomes visible when 38° C. is reached or exceeded, wherein said first portion and said second portion are arranged such that said first portion and said second portion are arranged such that at least a part of the first portion and second portion of the colored element are situated alongside each other wherein when the first portion has spaces without conventional ink, the second portion of the colored element also covers the paces and the color of the thermochromic ink is, below about 38° C., as similar as possible to that of the conventional ink; and (d) the packaging material is suitable for a pharmaceutical product.