# 85D - 1867 10c Washington, Green, "Z" Grill

U.S. #85D
George Washington

• One of six stamps (85A-85F) embossed with the “Z” grill
• Only six examples known to survive
• Grill measures 14 to 15 points by 17 or 18 points
• Z grill impressions are “points down”, making grill pattern often visible on front of stamp          

Stamp Category:  Definitive
Series:  1867-68   
Value: 10c                                                                                                                                  Issue date:  1867                                                                                                                 Printed by:  National Bank Note Co.
Quantity printed:  2,000 (estimated) 
Format:  Printed in sheets of 200 stamps, divided into vertical panes of 100 each
Printing Method:  Engraving
Perforations:  12
Color:  Green

Why the stamp was issued:  #85 covered the international postal rate to many foreign countries.

About the printing:  

The design was engraved on a die – a small, flat piece of steel.  The design was copied to a transfer roll – a blank roll of steel.  Several impressions or “reliefs” were made on the roll.  The reliefs were transferred to the plate – a large, flat piece of steel from which the stamps were printed.  The grilling process was applied to the stamp after printing.

About the design:  The image of Washington is based on a portrait by renowned artist Gilbert Stuart.  Stuart painted at least 100 portraits of Washington. 

About the series of 1867-68:  The designs of this series were the same as those of the 1861-66 issues. 

Grills were introduced because the U.S. Post Office department was worried about the removal of cancellations, allowing for fraudulent reuse of a stamp.  Grills were made by embossing the stamp with a pattern to break down paper fibers, allowing cancellation ink to soak deeply into the paper.  This made it impossible to remove cancels, as even regular pen ink, used to manually cancel stamps at smaller post offices, would penetrate the fibers. 

There were several proposals for different ways to solve the problem.  Charles Steel, who oversaw stamp production at the National Bank Note Company in the 1860s, developed and patented the grilling method.  He was granted a patent for the process on October 22, 1867.  Steel also saw the process as helping stamps adhere better to mail. 

According to Steel’s patent, “The object of my invention is to produce a stamp which shall stick better than usual, and which it shall be impossible to fraudulently remove and use again.”  Steel’s simple machine used a roller pitted with either small depressions or small raised pyramids to break fibers in the stamp paper.  The rollers with depressions created a “points up” pattern while those with raised pyramids made a “points down” pattern.

The United States was the first country to issue grilled stamps and was the only country to do so until the mid-1870s, when Peru also began using grills.  The National Bank Note Company was responsible for producing both countries’ stamps.

Grills were used for only nine years – 1867 to 1875, encompassing the 1869 Pictorial Series (#112-22) and the 1870-71 Bank Notes (#134-44).  The National Bank Note Company attempted to find the perfect grill size by experimenting with various versions.  The large A, B, and C grills weakened the paper too much.  As time went on, the rollers were ground down to produce smaller-sized grills that would prevent the stamp from tearing easily, but wouldn’t let the ink penetrate the paper.  That resulted in grills too weak to do the job.  There was also the issue of extra expense, plus, the reuse of stamps wasn’t as prevalent as postal authorities feared.  This historic postal era had come to an end. 

In 1916, William L. Stevenson measured all known grill sizes and categorized them.  He gave each a letter from A to J.  The exception was the “Z” grill, as he was unsure to which grill family it belonged.  Nor did he know which family it preceded or followed, so he used the letter “Z” to signify the unknown.  It differs from other grill patterns because the tiny ridges on each peak are oriented horizontally instead of vertically.

Grills are classified by the dimensions of the grill pattern and are measured in millimeters or by counting the number of grill points. There are eleven major classifications:

“A”           Grill             Covers the entire stamp

“B”            Grill            18x15mm            (22x18pts)

“C”            Grill            13x16mm            (16 to 17x18 to 21pts)

“D”            Grill            12x14mm            (15x18 to 19pts)

“Z”            Grill            11x14mm             (14 to 15x17 or 18pts)

“E”            Grill            11x13mm             (14x16 to 18pts)

“F”            Grill             9x13mm              (12x16 to 18pts)

“G”            Grill            9½ x9mm             (12x11 to 11½ pts)

“H”            Grill            10x12mm             (11 to 13x14 to 16pts)

“I”            Grill              8½ x10mm           (10 to 11x10 to 13pts)

“J”            Grill              7x9½ mm             (9 to 10x12pts)

The letters classifying the various grill types do not denote the size, shape, or appearance of the grills. They indicate the order in which each was discovered.

Mostly visible only from the back of the stamp, grills may be felt by lightly running a fingertip over the surface.  Depending on which roller was used, the pattern is “points up” or “points down.”  The ridges on an indented roller force the paper into the recesses, creating raised points, while a roller with raised pyramids will cause the points to be forced down into the paper, forming a series of depressions.

The “D” grill on #85 was one of the two first “points up” grills.  The other was #84 Andrew Jackson.  This grill was rejected after a small quantity was issued.         

Grilling resulted in some of the greatest U.S. stamp rarities, including the legendary 1c “Z” Grill (U.S. #85A) owned by Mystic Stamp Company for several years.  Part of the William H. Gross collection of classic U.S. stamps, the 1c Z Grill sold for almost $4.4 million dollars at auction in June, 2024.