Thursday, 21 March 2019

37p Machin Fluoresent Head

It still amazes me that these days I tend to forget more than I learn. Old age I guess!!

Anyway, the story goes that whilst I was looking through some stock books for stuff to sell on eBay I came upon eight copies of this particular 37p stamp, together with eight normal stamps of the same value.

Now that I  have the stamps in front of me my memory has returned. It occurred to me that I have never seen these advertised as a variety, so I thought I would pass the information via this blog on to other collectors.

The Machin in question or should I say, that I am referring to is the 39p 37p Amethyst OFNP/ PVA 2 B phos bars without afterglow.

This was once printed and issued with a unusual difference. The head when viewed under UV light appears to shine. I have tried to show the effect in a photo, but the flash does not do it justice. The effect is quite startling and very spectacular.

It has been determined that the reason for this is that it occurred as a result that one of the plates used to print the head in a light colour produced an initial error in the colour registration. To rectify the problem and achieve the desired result the printers used an optical brightening agent (OBA), this was added to the ink which was used to print the head only. The compound  was similar to that used to brighten OBA paper. 

The transformation was quite unintentional that the head changed when viewed under a UV light, it glowed a bright Orange- red. Amazing stuff eh?

Anyway to finish, a couple of these oddities (offered together with a normal for comparison) will be added to my eBay sales lists.

Alternatively if you want a copy of each for a fiver (post free UK only) write to me at

1 comment:

Anonymous said...

Thank you for the stamps. As you say Roy - amazing stuff