In the past, choking hazards involving pen caps were reported in several countries. As a result, product safety organizations encouraged manufacturers to redesign pen caps to reduce the risk.
Today, many major pen brands design their caps with ventilation holes specifically for this reason.
This small design improvement has become one of the most recognized safety features in everyday stationery products.
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Another Hidden Benefit: Air Pressure Balance
Besides safety, the hole can also help with air pressure balance inside the pen cap.
When you place the cap on the pen, the small hole allows trapped air to escape. This makes it easier to cap and uncap the pen smoothly without creating pressure inside the cap.
This prevents ink from leaking or being pushed out due to pressure changes.
