Traditional handwriting ink, invented in China and India in ancient times, blurred during printing.

The faulty stamps were inverted during printing, so the yellow background does not fit around the building, leaving a notable white space.

The roll was constantly wound and rewound during printing.

Also, applying too much vertical pressure on the stamp during printing can cause the raised relief features to flatten against the substrate.

The dies were altered several times during printing, yielding dozens of minor variations.

Color was added during optical printing.

The first is their placement on the sheet during printing, and the second reason is due to the "rubber band" factor.

All characters should be able to resist the pressure during printing.

If the contaminants they contain get through filters, they can make sheets of rolled paper stick together, causing tears during printing.

Soy and vegetable inks are used during printing.