PJ Greetings' Stamps are "pre-inked". What does that mean?

The difference of pre-inked versus self-inking stamps is the quality of the impression and how long the stamp lasts between re-inkings. Pre-inked stamps are top quality and provide a solid, crisp impression. Pre-inked stamps have the ink impregnated in the rubber die and with a simple press, the impression is done. Self-inking stamps have an inner working mechanism where the rubber die retracts back up and stamps the inner pad, resulting in the stamp pad dry out over time faster than pre-inked stamp would. Pre-inked stamps offer tens-of-thousands of more impressions without re-inking and the impressions are crisper than self-inking stamps.