Business Sheets - Type 1 & Type 2 slits

Security stamps were first issued way back in 2009, with the counter sheet stamps being issued in February and the Business sheets having a philatelic release on 31 March. 

Specialists soon found that the security slits existed in various types - each U-shaped slit could be coninuous, or divided; and the size of the division also varied, and some basic stamps existed in both types, especially those from business sheets.   I highlighted some of these differences at the time as did Roy on MachinMania.  

I said at the time that the Type 2 slits were more difficult to see on the 1st class stamps than on the 2nd.
In the few instances where we have had sufficient to sell in our online shop, I include the following warning in the description of the Type 2 (divided) slits:

NOTE: the breaks in the U-shaped slits are not consistent in the sheets, and some are very difficult to see. Royal Mail advised that, at least for some printings, the 'breaks' were made individually to the existing die-cutter.
 
The differences are so difficult to see on some sheets that when filling orders I carefully examine the stamp through a magnifying glass, holding it up with the light behind it to be sure which one I have.  Recently I found some Business sheet tops that I had put aside. Having determined from the date (27/05/09) that they are the 2009 (ie undated) issue, I checked whether they had type 1 or 2 slits, and that's where the fun begins.

One 1st class sheet top has a mix of stamps.  
The first two stamps in the row definitely have 4 divided slits - type 2.  
Stamp 4 has 4 undivided slits, type 1 - absolutely no indication that the die-cut has has extra breaks added.  
Stamp 3 has a fairly obvious break at the foot of the left slit, and a barely discernable break at the top of the right slit.  The top left and lower right U-shapes are complete, ie Type 1!

Now maybe others found all this out - and published it - at the time, but I don't recall reading it then.  It does make one wonder how these should be identified, distinguished and even collected.  But it does mean that I have added some more Type 1 2nd class and Type 2 1st class from 2009 to our shop. So if you've tried to buy and found we've been out of stock, come back - they're here!

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