Hello,  another  piece on sorting Machins.  I must have about 1000 of these and trying to decide what they are is very difficult. Are they from a sheet, Booklet, or coil for example. And what issue? 1993 - 2008 or 1998 - 2001 issues?, covering SG 1664, 1665, 1670,  or 2039.   

The above is just one page of 64.  Some lighter shades, but that really doesn’t help. Or does it?   I have sorted by perforation – 15 x 14,  some 14½ and I even found a few perf 14.   I won’t bore you too much but if any reader has any helpful tips and tricks to distinguish even just 1993- issues from 1998- I would be interested to hear from you. you can write to me at cddstamps@gmail.com

And, if you look at the image below you will see one way to start to differentiate some of the stamps. 

The Phosphors bands show differently, for example – very bright white, duller white, greyish and yes, yellow.  From 1997 onwards for example both Questa and Walsall used long wave phosphor which gives a violet response viewed under ultra violet light.    I have not found any yet but in the image below you will see two stamps with Yellow flour. The others show Blue flour – actually white to the naked eye -  The yellow is from a 1993-  issue so I know that is SG 1664.  The Blue flour is from the 1998- issue ( I think) so SG 2039.

A good catalogue does also help.  Must get my Deegam CD out and get reading.

Enjoy your stamps. Best wishes   Michael

cddstamps.com  -  where you can fill a few gaps in your Machin collection from the 1700 we have listed, with more to be listed as we get organised.