Plus Guard Your Id Value Set, Blue The large stamp and refill features an encrypted pattern and oil based ink to completely cover addresses and sensitive information on junk mail, credit card offers and receipts The mini roller stamp and refill are perfect for travel so private information can be blocked off of receipts, hotel bills, travel documents, etc Blocking out personal information on paper items allows curbside recycling without worrying about others seeing your private info Eliminate noisy, messy, expensive shredders with the guard your id products Not to be used on glossy papers, photographs, or slick surfaces where the ink can be rubbed off, Best on matte finish envelopes, copy paper without a shine