Tonight a piece by Roy Simpson, Machin Man. As informative and educational as ever.
I hope you enjoy this.
When surfing eBay for potential bargains, I always buy my stamps in multiples. MV Coils are a particular favourite of mine. You may ask why?
Recently I purchased a small collection of multi value coils for just a few pounds, amongst them where 3 that are quite rare. These were early 5p Multi value Machin coils 1 x 2p + 2 x ?p + 2 x 1p on Original Coated paper with gum Arabic.
Whats so special about that? Well, the answer is "know what to look for"..
Sometimes the seller may not realise what they are offering, and in job lots it is possible to pick up these rare items for peanuts. These coils with gum arabic and with a silicone coating carry a very large premium over the norm and are catalogued at a staggering £250.00 per coil.
In 1972, by order of Royal Mail, certain stamps from this issue were experimented on by the printers , thus they have a silcone coating over the printed image.
Gum Arabic was a problem for Royal Mail, not only did it have a tendancy to curl, stamps often stuck together. The silicone was introduced in an attempt to stop stamps sticking together, this was a problem for Royal Mail as it often happened during humid , or wet conditions whilst stamps were stored in the vending machines.
After a six month trial it was found that the silicone coating did not solve the problem completely so the experiment continued, with a change of paper to Fluor Coated / Gum Arabic, these coils with FCP are not rare as stamps from the original trial as they ran for approx 2 years up to 1974 when, the gum was changed to PVA Dextrin .
With the introduction of PVA Dextrin the problem seemed to be cured.
More information on Multi Value coils (if required) can be found on Roy's brilliant website at click here
Enjoy your stamps.. Best wishes.. Michael