Answer: overprinting

AnswerCrossword Clue
overprintingPrint additional matter on (a stamp or other surface already bearing print)
overprintingPrint too many copies or too much of
overprintingOVERPRINT, to print over something already printed
overprintingMake (a print or other positive) darker than intended
overprintingPrint (additional matter) on something already printed