Minor mis-registration of colour, phosphor or iridescent printing are not uncommon, although few of the phosphor shifts have warranted much attention unless they are totally clear of the perforation hole. Then they are described as 'short-band' foot, top, left, right as appropriate.
The same attention has not been given to shifts of the iridescent printing on security stamps although it is easier to see, especially if the iridescent ink is tinted and shiny, and shows up on the white margin of the stamps.
Melvyn D has sent some pictures taken with a USB microscope showing some quite spectactular shifts on recent stamps. My USB 'scope doesn't have UV light, and it doesn't have Mac-compatible software although it can still be used. But maybe I shall have to investigate some better equipment.
There are two examples of phosphor shifts on the 5p. On the first the phosphor is shifted dramatically up to the foot of the elliptical perforation, giving a 'short-band foot':
With the second, the movement is even greater, which gives only one 'short band foot' on the sheet, with all the others having interrupted phosphor - which is also shifted to the right, meaning that it is inset at left.
The same attention has not been given to shifts of the iridescent printing on security stamps although it is easier to see, especially if the iridescent ink is tinted and shiny, and shows up on the white margin of the stamps.
Melvyn D has sent some pictures taken with a USB microscope showing some quite spectactular shifts on recent stamps. My USB 'scope doesn't have UV light, and it doesn't have Mac-compatible software although it can still be used. But maybe I shall have to investigate some better equipment.
There are two examples of phosphor shifts on the 5p. On the first the phosphor is shifted dramatically up to the foot of the elliptical perforation, giving a 'short-band foot':
With the second, the movement is even greater, which gives only one 'short band foot' on the sheet, with all the others having interrupted phosphor - which is also shifted to the right, meaning that it is inset at left.
The 10p has phosphor inset at the right, and the 20p at the left.
What does all this suggest? All these are ISP/Walsall printings, suggesting that quality control - for the sheets at least - is less stringent? But similar insets have not been seen on recent Christmas stamps which are also printed by Walsall. It's clear that Royal Mail are not too concerned about the iridescent printing - after all if these valued stamps are self-adhesive then they are from counter sheet printings, the only others being gummed from prestige stamp books.
But the important thing for phosphor is that there should be two clear bands of decent size. After the pandemic is over they may get back to separating 1st and 2nd class mail and using the phosphor for segregation.
The other thing that these pictures demonstrate is that with the right equipment you can collect stamp variants that are not immediately obvious to the naked eye, and show them in your collections, exhibits, or in club displays (when they return) with suitable illustrations like these.
But the important thing for phosphor is that there should be two clear bands of decent size. After the pandemic is over they may get back to separating 1st and 2nd class mail and using the phosphor for segregation.
The other thing that these pictures demonstrate is that with the right equipment you can collect stamp variants that are not immediately obvious to the naked eye, and show them in your collections, exhibits, or in club displays (when they return) with suitable illustrations like these.
If anyone does collect these Melvyn has an excellent assortment on ebay seller name georgie-dad.
ReplyDeleteI think Melvyn's pictures are excellent. Maybe he could share some information on the equipment he is using as I know myself and I am sure others would be interested.
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