Multiple crown Wilding stamp papers

Sorry about that Khj, it's the British Film Industries policy : and not mine !
Paperchase

No big deal, I'm sure they have their good reasons. I did go to the Ivybridge Heritage website, and they had a lot of written info about Stowford Paper Mill.

Do you live in the UK brightonpete ? If not, this could be the reason why. Paperchase

The need for a whiter paper became apparent as the technology improved on the automatic sorting system and after further trials at the Dollis Hill establishment, the GPO announced in 1962 that the current cream type of paper to print their stamps would no longer be used, and would be replaced by a whiter version, the source of which was produced at the Stowford paper mill in Ivybridge South Devon.
In order to achieve the difference of paper, the water drawn from the river Erme was to be filtered as it was believed that this would reduce the coloration in the water that was currently used to manufacture the paper.
An article on the subject was composed by the late professor Austin Barnes and published in the British philatelic journal in 2020 Vol 58 no.3 on pages 68/69 and can be read as follows >



After studying these Wilding papers, it would appear that not only are there variations in the papers that have been depicted in the Stanley Gibbons specialised part 3 as specified by the GPO in their declaration of 1962 over the changeover from cream to whiter papers, but several other variants of paper has also been used to print later issues after the declaration was made, it concerns 3 unlisted papers that appears to have been overlooked in the past, appertaining to the following :-

(1) A paper that appears to be encrusted with fluorescent fibres/flecks in the embodiment as seen on various dominations of the 9½mm violet phosphors printed on a whiter paper, possibly caused by the use of rags that contained high amounts of stilbene dyes used in the production of many detergents, this type of contamination was first seen around 1964 and gradually increased as time went by, other values have also been so affected, add to the fact that there could have been a possible change of rag supplier around that time.
(2) A cream type paper similar to the original creams but of a more translucent nature, used to print some of the 4d 9½mm violet phosphors first issued in 1967, and yet again other values have also been affected similarly which includes some of the 4d deep ultramarine (plain) first issued in 1965. These findings indicate that an attempt to remove the fluorescent fibres containing stilbene was made by the use of chemical in a process known as oxidation whilst still in the pulp stage, in order for degradation to be achieved.
(3) A fluorescent paper has been used to print various denominations, some good examples have been found of the 10d 9½mm violet phosphors, this type of paper was created by the addition of optical brightening agents in order to camouflage/mask the offending contaminants, other values printed on this type of paper are also known but not as prolific as the contaminated ones ranging from 1d to the 1/6d with a few exceptions.

I will endeavour to show you examples of the above three types of paper that are unlisted in specialised catalogues, these will cover normal definitives, regionals and some commemoratives to a varying degree.

To be continued ............

Post 1962. Cream (translucent) type papers discovered
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It was stated by the GPO that only whiter papers would be used to print their postage stamps, but a problem had arisen in the form of contaminating fluorescence particles found within the embodiment of some of the papers used to print their stamps and a remedy needed to be found.

The Stowford paper mill employed some of its staff to inspect incoming rags that was used to produce the paper as a first stage of the papers production, removing such items as buttons, zips, foreign objects such as insects or even a dead mouse, the one thing the "rag girls" could not remove was the fluorescence (stilbene from washing powders) in some of the rags that arrived mixed in with the normal rag and was therefore left to the boffins to resolve.
The chemists at the paper mill was faced with a dilemma as to how to rectify the situation with regards to the removal of this type of contamination, and must have initially thought of a remedy by using a process known as oxidation whilst the paper was still in the pulp stage, as being most effective in the degradation of the fluorescent particles/flecks that was the source of their problem encountered. The idea that the use of chlorine dioxide or ozone would nullify the fluorescence in the embodiment, being more susceptible in the solution phase (pulp stage).
Apparently, by using this method of removal, the process created a more " yellowish (cream) type of paper " similar to the earlier creams produced prior to 1962 but of a more translucent nature, here are two attachments of the 1/6d phosphor giving a good example of an oxidised paper compared to the whiter listed version as seen under long wave ultraviolet light.......





The same principal applies to some of the regionals that was also printed on a cream oxidised paper, here is an example of the 4d Guernsey plain stamp that was first issued on the 7th of February 1966, with quantities in total sold of 4,415,040 . Sadly, only one type of paper has been listed in the specialised catalogue, which fails to list the cream paper version !
Here they are for comparison ........






Due to these cream papers being omitted in specialised catalogues and the amount currently in the hands of collectors, there can't be many available for purchase, making them a sought after item, or could it be the whiter paper that's the scarcity ?
Do you have both variations in your collection ?


More to follow.........

I have moved some posts from the thread below because they became somewhat irrelevant to that topic and are better suited for future reference under this more specific topic. 

thestampforum.boards.net/thread/9286/stamp-catalogues-comparability?page=3

If I see other posts on this topic they will be moved here or to another more specific thread.
Londonbus1

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There is an interesting article jdtrue66 based on the study of stamp papers composed by Chris McFetridge, a Canadian dealer of St. John New Brunswick that I think will be of interest to you, it can be found on the following site

brixtonchrome.com/pages/how-to-study-a-stamps-paper

It makes interesting reading.

Based on my studies over the last 4 years all in all, 6 different papers were used to print stamps with a multiple crown watermarked paper by Harrison and Sons of High Wycombe and a compilation of them is listed below and can all be clearly defined with the use of long wave ultraviolet radiation when comparing like with like :-

(1) A cream type of paper with an opaque embodiment when comparing to later issues, last officially used in 1962 bar the odd exception, the one used in the scan is of the 6d 1961 Parliamentary Conference.

(2) Using a similar stamp as (1) but showing the printed side is another version known as chalk surfaced paper first appearing on the 3d GLO of 1960, with the first ever coated stamps being back in the reign of Edward Vll being more highly fluorescent once radiated.

(3) A whiter type paper (so called) used after 1962, thought to have been created by the use of filtrating the water from source of supply.

The first 3 papers used have been well documented, but of the last 3, numbers four, five and six no mention has been given them but have all been classified as whiter papers as a "catch-all" scenario, irrespective of the differences. I now come on to the unlisted ones :-



(4) A contaminated paper created and used (inadvertently) of rag that was high in detergent content (stilbene) that was highly fluorescent as supplied and mixed in with the normal rag, that is easily recognisable when viewed under long wave UV.

(5) A cream type paper similar to the pre 1962 ones but of a more translucent nature that have been discovered on printings much later, this one being the 4d deep ultramarine with 9½mm phosphor bands issued early 1967, this type of paper was in my estimation, created by the use of chemical degradation known as oxidation, but this left a residual paper totally lacking in florescence as against the intended whiter paper required.

(6) A fluorescent paper created by adding additional optical brightening agents to the mixture whilst in the pulp stage, in order to conceal/mask the contaminating fluorescent fibres that seemed to be ever increasing since around 1964/5. By using this procedure, not only would it solve the contamination problem but also enhance the capabilities of the ALF section of the letter sorting system, giving a much needed whiter paper when letters were processed.

Unfortunately only three of the above variations of paper 1-3 have been specified in specialised catalogues.

This next attachment shows 5 varieties more clearly excluding the chalk surfaced stamps.



Seeing is believing !

Looking at these examples I have to wonder are we talking about true fluorescence looking at the white stamp is you light it with 400nm and it reflects 400nm that is not fluorescence. It would have to reflect back in a different range. Yes this would detect shades of color of paper and if that is what your looking for great. For example some body fluids that you cant see will be visible under UV regardless of the color that are sitting on. Under full spectrum you cant see them.

Still a interesting subject  

jdtrue66
interesting.....I am a newbie in UV lights - I have both and know how to use it for Canada but elsewhere.......

Thanks !

René

Here is an article based on this particular subject >

Optical brightening agents and fluorescence in fabrics and paper
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en.m.wikipedia.org/wiki/Optical_brightener

This will give you some idea based on my findings

(Stamp papers+varieties) & (ultraviolet light) complement each other angore , as it's a bit like love and marriage "you can't have one without the other"

Some varieties of papers and printing inks can only be distinguished by the use of an ultraviolet light.