Instructions
Turn over the head vase.
Inspect the bottom for a stamp, black mark, foil label or paper label.
Find a black stamp or mark that has a beginning capital letter and numbers, such as "C1234." The mark might also include company identifying information such as "National Potteries, Bedford, Ohio," or "NAPCO." Some marks also say "Hand Painted" and provide a date.
Locate an original foil seal that states "National Potteries Co." and "Made in Japan."
Find a paper label with wording identifying "Napco" or "National Potteries Co" as a part of the wording. Examples of wording on Napco paper labels include: "Napcoware, Import Japan," "A Napco Collection," and "National Potteries Co., Cleveland, OH, Made in Japan."