Custom Return Address Stamp - Self Inking Custom Stamp Custom Return Address Stamp - Self Inking Custom Stamp To customize, please click on the 'Customize Now' button on the right. Custom Return Address Stamp is self inking. Stamp can last for up to one thousand impressions before being re-inked. Custom Address Stamp impression is approximately 1" x 2.5". All stamps are made to order. Most orders ship within 24 business hours.