Why do Pen caps have a tiny hole at the top? The hidden reason will leave you shocked
The hole in pen caps balances air pressure. When you close a pen, the cap traps air inside. Without a vent, pressure differences could make the cap hard to remove or even cause ink leakage.
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The hole in pen caps balances air pressure. When you close a pen, the cap traps air inside. Without a vent, pressure differences could make the cap hard to remove or even cause ink leakage.
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