Pocket Signature Stamp - Self Inking Pocket Signature Stamp - Self Inking Customization Instructions: Click on 'Customize Now' on the right and follow instructions. Amazon's upload feature accepts JPG and PNG files. If you are having any issues with uploading your file, please don't hesitate to contact us. The is a self inking stamp that is built to last for thousands of impressions. Comes in Black ink Approximate impression size is .75" x 1.875"