A partial missing print occurs when ink cannot reach part of the printing surface because of an obstruction or a defect in the paper, such as a folded sheet, paper crease or foreign object trapped between the paper and the printing surface.

If part of a sheet folds over during printing, a portion of the stamp design may be printed on the reverse of the folded section, or the ink may instead be transferred to the impression surface. In the latter case, the reverse of the next sheet may acquire a partial machine offset.

Partial missing prints can occur with any printing process and on many types of paper. Related production varieties include paper folds and printing flaws caused by foreign material between the paper and the printing surface.

In the example above, the upper-left corner of the printing sheet folded underneath during printing, so the ink in that area was transferred to the impression surface rather than to the paper. The sheet was unfolded before perforation, resulting in a normally shaped stamp with part of the design missing. A partial machine offset may at the same time have appeared on the reverse of the next sheet printed.