Unlock the secrets to incredible pen experiments and tricks that will amaze you! From turning a regular pen into a phone ...

Explore the detailed process of manufacturing whiteboard marker pens in a Korean ink pen factory. From assembling the casing to filling each pen with high-quality ink, every step ensures smooth ...

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In the Middle Ages mixtures of lemon juice and vinegar would be used to write an invisible message that could be revealed by exposing it to heat. In one famous example, invisible ink created from ...