Other evidence such as color of the ink used or watermarks in the paper may be of use in reconstructing plates.
Philatelists have made extensive efforts in plating many of the Nineteenth Century Classic postage stamp issues and have written a number of books on plating different stamp issues.
Through painstaking study of the stamps, philatelists were able to reconstruct most or all of the first Die II's 70 plates.
Later philatelists were assisted when reference copies and high quality photographs of the original panes kept by the British Government were made available for inspection.
The other early engraved stamp issues of Great Britain have similarly been plated.