1.What is the shelf life of this paper? How long can it be stored before it changes color? We have different kinds of thermal paper which has 2 ~ 5 years of life. 2.What are your lead time? The first 20 feet container order will be delivered within 15 ~ 20 days. 3.How can I get samples? We can make out the free samples according to your requirement within 1 ~ 2 days, But express fee should be paid by customers.