First days cover from St.Thomas, inverted frame - printing 3 pos 51.
Double cancels are very unusual.
The inverted frame was first identified in 1917, so its use on philatelic mail was not deliberate.

Printings Involved

The most commonly used bisected 4 stamp was perforated 12 3/4 and is from printing four. It is very hard to separate it from stamps of printing three. 

Print 3: dull greenish slate blue/light yellow brown - one inverted frame in position 51.

Print 4:  clear light blue/yellow brown - 11 inverted frame in position 51 and 91-100.

Stamps from printing two was perforated 14 x 13 1/2.

Print 2 stamps are not as commen print 3 and 4.

The stamps from printing two have a greater catalog value.  Printing two stamps are likely stamps the collector han stashed away and put into use to perhaps generate another philatelic variety.

One person, a Mr.Duurloo, produced a number a small covers  (95 x 54 mm- see photo) with stamps from printing two that were canceled St.Thomas.

Stamps from printing two are also used on covers mailed at Christiansted and Frederiksted.

Covers bearing bisected stamps from printing one are know but are very rare - I have only seen one cover with printing one. 

It is not known how many stamps were biseced and used, and estimates have ranged from as few as 2.500 to as many as 53.000, but couuld easily have been more than 10.000 letters.




The diverted frame is usually defined by the upper left scroll design, but may also be be defined in the bottom right corner. a bisected stamp can only have one of these corners.

Duurloo mailed nimerous tiny covers on this date. The cancel has the appearance of having been cleaned, and has the spelling with a “period” that is not very common. Only 5% of bisected 4 cents stamps were mailed in may.