The drying time of paper corner protectors depends on many factors, including environmental conditions, paper humidity, temperature and ventilation. Typically, the time it takes to dry paper corner protectors can range from a few hours to a day or so, but this may vary depending on the specific situation.

Here are some factors to help determine drying time:

1. Humidity: A high-humidity environment will prolong the drying time, while a low-humidity environment will speed up the drying of paper.

2. Temperature: A warmer environment usually helps dry paper faster.

3. Ventilation: Adequate ventilation can help paper dry faster, especially when drying outside.

4. Thickness and moisture content of the paper: Thicker or wetter paper will take longer to dry.

5. Outside weather conditions: Sunny, dry weather is usually more conducive to paper drying, while humid or rainy weather may take longer.

Therefore, you need to determine the drying time of the paper corner protectors according to the actual situation. As a general rule, place your paper corner guards in a well-ventilated area, making sure to avoid high humidity and damp conditions so they can dry as quickly as possible.