Stewart Superior-Ultra Cleaner Refill. Ultra Clean is the most effective stamp and craft cleaner ever developed. Cleaning even the most difficult permanent stamping inks! Ultra Clean's special formula lasts even longer so you can clean more stamps with less cleaner! This bottle contains 8 ounces of Ultra Cleaner. Conforms to ASTM D-4236, EN71. Keep away from children. Not to be taken internally. Eye irritant. Made in USA.