[1] The "Z" pattern, unique among grill templates used by the Post Office because it incises horizontal ridges into the stamp rather than vertical ridges, was replaced within a very short time, for stamps with the D- and E-Grills were already being postmarked in mid-February.

Later, in late October 2005, Sundman traded this Z-Grill to financier Bill Gross for a block of four Inverted Jenny stamps worth nearly $3 million.

[4] Both Z-Grills were on display at the National Postal Museum along with the first part of the Benjamin Miller Collection from 27 May 2006 until 1 October 2007.

This anomaly arose because Scott created its system long before the Z pattern gained general recognition as a separate variety of grill (which did not occur until the 1910s).

This expedient enabled Scott to retain the existing numbers for all subsequent stamps, beginning with the E Grill issues (#86-91).

Additionally, the number of points vertically and horizontally matter, but existing reference material can be confusing.