Here's why:
* Iodine Test: Iodine is commonly used as a test for the presence of starch. When iodine comes into contact with starch, it forms a dark blue-black complex.
* Bond Paper: Bond paper often contains starch as a filler material to improve its strength, texture, and printability.
Therefore, when iodine is painted on skin that has come into contact with bond paper, the iodine reacts with any residual starch on the skin, creating the characteristic blue-black color.
