Dr. Sun Yat-sen, Black Surcharge - 黑色套印的孙逸仙博士 $50 on 30c Dull vermilion

Without Gum

Country China
Denomination
?
Face value of a stamp, usually printed on the stamps.
— Glossary

$50 on 30c
Color
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Original catalog color of the stamp.

Dull vermilion
Print method
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Method of process of imprinting designs on paper.

Typographed
Perforation
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Holes punched between stamps to make separating easier.
— Basic philately terms for amateurs

10 1/2-11, 11 1/2-12 1/2, 13
Watermark
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A pattern embedded in a paper during stamp producing process.
— Basic philately terms for amateurs

Unwatermarked
Issue Date
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Date inscripted on a stamp or cancellation for used stamps not necessary correspond to real date of stamp issue.
#
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Catalog number of stamp.
— Basic philately terms for amateurs