1. oil: ink seal is required, and photosensitive ink is used for photosensitive seal.

2. Duration: The inkpad seal needs to be stained with inkpad repeatedly every time it is stamped, while the photosensitive seal can be stamped only by adding ink once until the ink consumption becomes lighter.

Generally speaking, ink seals need to be replaced frequently, while photosensitive seals can only be used continuously by adding ink regularly.