I can now report the finding of two different papers used to print the 1970 5d Christmas stamp, on comparison one of which appears to be of a non-fluorescent type set against a quite highly fluorescent one that reacts strongly under long wave ultraviolet light.

The fact that these paper differences have been ignored by major catalogues means that many collectors are not aware of such varieties being in existence, a difference in a stamps paper is as important as to the way it was printed and I am sure that some other QE ll issues have also been likewise affected by similar differences.

I have selected 4 used examples of the said stamp (two frontal and two reverse images) in order to exhibit the differential found..........

The type of paper that a stamp has been printed on can make a vast difference regarding its scarcity and value of that particular stamp in question. Neither of the above-mentioned varieties of these particular stamps are worth much, but the difference is quite obvious when inspected under long wave ultraviolet light and adds a new variety for the collector to bear in mind.

An extreme example of a paper variation was that of the Canadian 2c large Queen discovered cancelled in 1870 as depicted by Mr. Christopher McFetridge of Brixton Chrome, a Canadian dealer, this is an extract from his article of studying a stamps paper, and is as follows. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



The complete article based on other paper variations and what to look for can be viewed by going to >>>
https://brixtonchrome.com/pages/how-to- ... amps-paper

A section of the article dedicates itself to variations on the luminosity of fluorescence found within different stamp papers when viewed under longwave ultraviolet light, and gives a list of intensities based on what is known as the Irwin scale in order to differentiate the various types of paper used in the printing of stamps, to be found in the table below.

Mr Frank Walton RDP FRPSL recently submitted an attachment showing quite a variety of papers that he had found whilst studying the multiple crown 3d value under long wave ultraviolet, however, none of the higher fluorescent or contaminated papers was exhibited in his collage, this alone gives rise of the need for further investigation and change !

Maybe an adaptation could be adopted and used for cataloguing British stamps on a similar basis, as the only differential or discrimination that is used at the moment in specialised catalogues for the multiple crown Wilding definitive papers is cream or white(r), whatever that means, and appears to be totally inadequate under the circumstances giving no scope for any of the variations that exist and abound.

Take the following 3 stamps as an example :-


The stamps depicted above are all currently classified in the SG specialised catalogue as being printed on a whiter paper simply because they were produced after 1962, irrespective of their colour, it's quite obvious that they are not the same and therefore should not be described as such.

I am sure that a device (indicator) could be produced whereby when radiated with a long wave ultraviolet light it would show all the variations given on the Irwin scale, and the stamp to be identified could be placed alongside for comparison, in a similar way that Stanley Gibbons produced the "INSTANTA" gauge to identify perforations : It's hardly rocket science is it ?

The description given of the 10d stamps below is specified in the notes by the SG specialised catalogue in that they were only printed solely on a whiter paper since the change-over date, obviously this is not the case, as one is on a cream paper with the other being printed on a highly fluorescent version, it's quite obvious there is no comparison between the two types of paper that they were printed on, yet are both listed and classified as being printed on the same whiter paper !

Admittedly there are some 10d values that have been printed on a whiter paper, but in total I have found three variations that co-exist.

A similar principal applies with the 4d plain definitive found in booklets first issued 16⁸/65 in which two distinct papers has been noted.

Therefore does SG's definition comply with the original trades description act of 1968 by discriminating against the other two types of paper used to print the multiple crown Wildings post 1962 ?

It just doesn't make sense !!!!! DOES IT TO YOU ?

Much research has gone into the study of whiteness and fluorescence in paper, the next site covers a multitude of citations made on the subject, you will find that there are many articles to choose from.

The fact that stamps have been printed on various papers with differences of whiteness and fluorescence gives credence for their inclusion to be added in all specialised catalogues.
https://scholar.google.co.uk/scholar?q= ... i=scholart

A further insight can be found on this subject of papers and their fluorescence by clicking onto the following site >>>>>
http://canadianphilately.blogspot.com/2 ... ial_8.html

If a stamp with a different perforation can be listed then why not whiteness and fluorescence in different papers ?

AND THEN OF COURSE THERE'S THE CONTAMINATED PAPERS TO CONTEND WITH !

WM.

Here is a good example that shows the difference between two types of paper concerning the printing of the 1/6d phosphor stamps, it can be seen that the stamps printed from cylinder 1 no dot are darker than those printed from cylinder 8 dot and that the darker paper has a tendency to show the phosphor bands being much brighter than the lighter paper under long wave ultraviolet light.

Therefore it is incorrect to state that the papers are the same, I'm sure that you can see the difference, but according to the SG GB specialised catalogue that is not the case as they are both classified as being the same.

With other papers used post 1962 some of the Wilding stamp values have been found to be very high in fluorescence when introduced to long wave ultraviolet light, but with some papers there is no fluorescence at all, being similar to the cream papers produced before the changeover in 1962 having a more translucent nature.
WM.

Fascinating stuff but still much too specialised for your average collector. Fluorescence has come into the 4 Kings catalogue to an extent with EVII listings and general comments about the fluorescent colour reactions between different printers on early GV stamps. I am sure it could be a worthwhile addition to the notes on the QEII stamps but would need to be backed up by facts and numbers to make sense. If there were deliberate changes in paper manufacture or soucing that information should be available.
looking forward to further comments.

What does make sense Jim in my humble opinion is that these variations of paper definitely exist that have been produced since 1962 that show cream, whiter, fluorescent and contaminated papers that are easily identified under long wave ultraviolet light, therefore I don't see anything too specialised or complicated for the average collector to understand, so don't belittle other collectors based on your own perception.

These 1/6d Wilding phosphors below was initially issued on the 12th of December 1966 and according to the SG specialised catalogue only printed using a whiter paper, but in my opinion that was not the case.


Are these two papers the same to you or do my eyes deceive me. What is your assessment and eventual conclusion on the matter ?

There's nothing too specialised or complicated to flummox the collector when differentiating the varieties found in these papers Jim, even a child can recognise the differences that have been created. Can't you ?

Alas, records in manufacturing errors are not always kept and/or released to the media, I mean who wants to hang out their dirty laundry in public ?
Referring to the contaminated papers as an example !

You may also have seen the report made by Dr John Sugden in his Woodstock column no.8 in "Stamp Collecting" 1968 by coming to the conclusion after trying to obtain information on the subject, quoting :
"As official silence is absolute". "
HIs words not mine !

What does it take to convince you that different varieties of paper exist, are you telling me that you can't tell the difference between a cream paper and a fluorescent one ? : See attachment below.

Tell me Jimusedcontrols, where in the SG specialised catalogue will I find contaminated papers listed, or has it been disguised as just another whiter paper as with the other varieties that exist ?

Excluding the contaminated papers you will find below the four variations of paper that have been used to print the multiple crown lower value definitives, which includes the regional issues between the years 1958 to 1967, and are comprised of the following >
(A) The original cream paper, being more opaque.
(B) A fluorescent paper with added optical brightening agents, having a more translucent embodiment.
(C) The more common whiter variety of paper also more translucent in nature than the original cream papers.
(D) An oxidised cream paper but of a more translucent nature than the original creams.

As I have already stated Jim, what could be simpler, or don't you find that to be the case, as I find there's no difficulty in distinguishing between the 4 different papers when seen under long wave ultraviolet light, all the 4 stamp papers depicted above are of the 1/3d regional for Scotland, stamps D are 8mm violet phosphors !

The designation given by the Stanley Gibbons part 3 specialised for papers B,C & D in the above attachment are classified as only being printed on a whiter paper.
You know, and I know, that that's nonsense ! ! !

Again the same features apply with these fluorescent 3d's

Along with these stamps from Northern Ireland on 3 distinct papers.

Looking forward to your further comments.
WM.

Since my original discovery of the 1970 5d Christmas stamp in May of this year, I can now inform you that another Christmas issue has been found to have been printed on two different papers, it concerns the 14p 1988 issue appertaining to cream and whiter papers, ironically the cream paper version on the printed/face side fluoreses much brighter than the whiter paper stamps, making the Star of Bethlehem appear to be larger.
< see attachment >

~~~~~~~~~~~~~~~~~~~
Here are 4 x 20p black Machin stamps first seen on the 26th of September 1989 three of which appear to be from booklets, when I tested these stamps by using the damp paper method, 2 of them tested translucent with the other two appearing opaque <see attachment>

I then checked the same stamps by using a long wave ultraviolet light, and this was the result that I obtained. >

Each paper appeared to be different, the 2 that tested as being translucent both responded to the UV but appeared to be different and of the 2 stamps that tested opaque one was much darker than the other, there are at least 2 major differences but it is possible that four different types of paper have been used to print these stamps rather than 2.
~~~~~~~~~~~~~~~~~~~
Whilst checking for other values that may also have been similarly affected, I came across this 1991 18p Christmas stamp issued on the 12th of November of that year, it appears to have been printed on a paper that has been contaminated by fluorescent fibres as can be seen in this next attachment. >

The image was taken under long wave ultraviolet light, reminding me of the multiple crown Wilding stamps with the same type of paper fault, it's just another repetition of what happened in the mid 1960s.
Here is the same stamp but featured in mono so as to enhance the contaminants found in the paper. >

Imagine, finding snow flakes on the back of Christmas stamps WOW !

In fact, it would seem that other stamps of the same denomination, issued roughly at the same time have also been printed on similar paper, here are a few examples >

With a modified image to enhance the contaminants found >

With a closer look at the 18p bright green stamp in mono. >

The 2p Deep green T2 (narrow value)
~~~~~~~~~~~~~~~~~~~~~~~~
Since reporting contaminated papers being found on the 1991 stamps, another value has been discovered being that of the 2p value type 2 Deep green shade, first seen on the 23rd of February 1988 having similar characteristics with the finding of fluorescent particles being impregnated into the paper and also found within two different types of paper, one being of a fluorescent nature with the other being on a much darker paper that can be seen under long wave UV
The first attachment being under normal long wave UV. >

The second attachment was taken under UV then filtered into mono in which to enhance the contamination found. >

It's emerging that many values have been printed on a similar type of contaminated paper during this period of time.
★See what you can find★
Any comments or findings from other members would also be welcome.
Thank you WM.

The use of different papers used to print the more modern British stamps during the reign of Queen Elizabeth ll is a lot more prolific and prevalent than first thought, especially since the removal of watermarks in the paper, much of which can be attributed to the automatic sorting of mail since the days of the Dollis Hill trials back in the late 1950s when graphite lines and phosphor tagging was first applied to stamps.

The application of fluorescent substances in paper (or the lack of it) has been one of the more obvious differences, either as a coating or within the paper itself when it was manufactured.

The next three values are mainly concerning some of the impurities or contaminants found within some the papers used to print these Machin stamps starting with the 19p bright orange first issued on the 23rd of August 1988.
THE 19p BRIGHT ORANGE AKA FLAME
~~~~~~~~~~~~~~~~~~~~~~~~~
Under long wave UV >

As seen in mono >

With the use of the damp paper method in conjunction with long wave UV I also discovered that the 19p had been printed on two distinct papers.
Normal spectrum >

Under long wave UV>

The next stamp features the 30p sage green printed on a phosphor coated paper first issued on the 26th of September 1989.
THE 30p SAGE GREEN PCP.
~~~~~~~~~~~~~~~~~~
As seen under long wave ultraviolet >

The same stamp filtered into mono >

And thirdly the 50p Ochre non-phosphor stamp first seen on the 21st of May 1980
THE 50p OCHRE NON-PHOSPHOR.
~~~~~~~~~~~~~~~~~~~~~~~
As seen under long wave ultraviolet >

A filtered version of the same stamp in mono >

The above image is reminiscent of pictures taken by the Hubble telescope relating to clusters of galaxies and nebula seen deep in our universe.
There are many other paper variations yet to be found.

A CHANGE OF PAPER.
~~~~~~~~~~~~~~
It would seem that once more history was repeating itself in the form of a contaminated paper used to print stamps that was full of fluorescent particles due to some of the rags being processed having been subjected to washing detergents that contained optical brightening agents (stilbene or derivatives).
Due to this problem encountered a new type of paper seems to have been developed and introduced whereby all fluorescence was purged from the mix by the use of chemicals during its manufacture and with no fluorescent coatings added to the paper in the finishing stages, leaving an absolute dead paper when seen under ultraviolet light, similar to cream type papers produced prior to the changeover back in 1962 with the Wilding issues.
One of the first commemoratives to have been printed using this particular new type of paper was the 1992 environmental stamps first issued on 15th of September of that year, here are 2 attachments taken of the 24p "Acid rain" stamp as seen in the normal spectrum and another under long wave ultraviolet >


This type of paper must have initially been experimental, as several commemoratives such as the 'Swans' and 'Marine Timepieces' issued later in 1993 can be found with both a fluorescent paper and coating, but from thereafter, all papers used to print commemoratives appear not have any optical brightening agents incorporated in either the paper or coating. This change over also applied to all definitives of around that time commencing with the "gold head" castles. WM

As far as I can ascertain, the first stamps to be printed using this new type of "dead paper" was the re-engraved high value 'castles' featuring a gold head and for the first time incorporating an eliptical perforation on either side of each stamp as an additional security measure.
The original high values printed on fluorescent paper and coatings was issued on the 18th of October 1988 with the new 'gold head' stamps replacing them on 24th of March 1992.
Here is a view of the two types of £1-50 stamps under normal light. >

The difference in the type of paper can easily be seen once subjected only to long wave ultraviolet light. >

In using this new type of "dead" paper to print stamps, the fluorescent contaminants found in some of the papers used previously would now be completely eliminated in respect to future printings, along with the problem of fluorescent coatings that had apparently been found to be fugitive, this new type of paper solved two long outstanding problems that had been previously encountered, and also gave uniformity in the quality control of things that was previously lacking on paper issues in the past.
Therefore any paper variations such as the differing fluorescences and coatings or actual base papers previously used, including contaminants can no longer be found due to the use of this new type of paper for the printing of stamps.
Having said that, over the years up to this changeover of paper there has been many variations produced, some of which have yet to be discovered and are possibly unrecorded as far as catalogue listings are concerned, the problem may have been resolved, but many stamps exist in varying degrees and condition prior to the change over to the"dead" paper being introduced from 1992 onwards.

Here is another stamp for consideration.

The 24p Chestnut on PCP
~~~~~~~~~~~~~~~~~
To add to the ever increasing quantity of stamps discovered that have been printed on a contaminated paper, I can now show you the 24p chestnut shade aka rust, printed on a phosphor coated paper that was first issued on the 10th of September 1991, the first attachment being taken under long wave ultraviolet light >

The second attachment is a mono version of the same stamps >

Here is a greater abundance of them due to the fact they were getting more common as time progressed, is it any wonder that the paper was changed in 1992
More of the little tykes including booklet stamps >

Another stamp to be found on contaminated paper is that of the 24p pictorial depicting winter time as the new type of paper had not yet been introduced on a permanent basis >

Quantities of the contaminating fibres (snow flakes) will obviously vary somewhat, mainly due to the inconsistent amounts of some of the contaminated rags used during the papers production whilst in the pulp stage.
Therefore any Machins printed on or before early 1993, wether they be commemoratives or definitives have a possibility of having paper variations similar to the ones already previously described.

According to specialised catalogues via information received from the GPO, 1962 marked the beginning of the production and issue of whiter papers only to print the multiple crown Wilding stamps and according to this information whiter paper stamps would be printed from then on.
Having looked at several values I am now beginning to wonder if this was the case, as the next three attachments does not seem to conform with the information given by the GPO at the time.
This first attachment shows 2 X 5/- "Castles" one apparently printed on a cream paper, whereby the lower one is on a whiter paper and below the 2 X 5/- stamps are 6 X 5d values each stamp appears to have been printed on a cream paper but were all cancelled in 1964 as can be seen in the next attachment. >

As seen in the normal spectrum. >

I have heard of late usage with some stamps but two years seems to be an exceptionally long period of time for the cream papers to have been used and from different areas of the country.

And finally, using the same stamps but observed from the reverse one can see the difference between the whiter paper of the lower 5/- value and the 6 X 5d values underneath >

WM.

It would appear that the more I look into these multiple crown Wilding papers, the more I am convinced that a cream paper was produced long after 1962 to print Wilding stamps, contrary to the post office declaration made of that year.
Here is further evidence to substantiate my belief that this was the case.

I have taken two blocks(6) of the 6d plain, both of which was cancelled in 1964, not only do they appear to be of a quite different shade to each other but from my findings they have also been printed on two different manufactured papers, whiter and cream, I have created 3 attachments in which to emphasise this point of the differences found.
The first attachment is of the two blocks appearing in the normal spectrum that show a distinct difference in the two shades, and with the cancellations clearly showing the date as being 1964. >

The second attachment shows the same stamps as previously but under long wave ultraviolet light, thus revealing the brighter and darker papers appertaining to what they have been printed on (white(r) and cream). >

The third attachment is of the same blocks as seen under long wave UV but in the reverse position, which clearly shows the difference in the colour of the papers used, whiter and cream. >

Still using the 6d value, here is a further exhibit of cream paper that was issued and cancelled in 1964, the three specimens depicted was cancelled in different years each coming from a different area of the country as can be seen in the following 3 attachments with relevant captions.
The first attachment are of the stamps as seen in the normal spectrum.

This second attachment is of the same stamps but as seen under long wave ultraviolet.

With the third attachment giving a reverse view of the same stamps in question.

Various other values that have been cancelled since 1962 onwards from different areas of the country have also been found to having been printed on a cream paper, therefore cream papers was issued and used for the printing of Wilding stamps long after the GPO's statement was made in 1962.
Here are further examples with the showing of the multiple crown (plain) 2½d T2 printed on both whiter and cream papers, issued and used in 1964 featured in 3 attachments. >

The first attachment has been taken in the normal spectrum depicting a block of 4 cancelled on 15th of December 1964 and a single stamp cancelled on the 21st of December 1964 both at King's cross station London, the block has been printed on a whiter paper whereby the single cancelled one has been printed on a cream paper, underneath them is a strip of 3 issued and cancelled in June of 1964 with a London "Old St." strike, this strip has been found to have been printed on a cream paper, please follow the 2 attachment sequences as taken under long wave ultraviolet light as proof of my findings. >


Or could it be that I am mistaken ?
Judge for yourself based on the facts given in relation to the pictures that I have submitted !
Thank you, WM.

I always thought that the Wilding multiple crown 2d left band (blue phosphor) had only been printed on a cream paper but I can now report the finding of this stamp being printed on a white paper.
The cream paper stamp issued and shown in the attachment for those interested as to when and where phosphor stamps were first distributed was from the Hendon Central post office London with a cancellation dated the 16th of October 1962 as seen on the right. >

The next attachment is of the 2 stamps as seen from the reverse in order to compare the differences in the paper seen under long wave UV.
The white paper version of this stamp does not appear to have been listed in the pre-decimal specialised catalogue and possibly requires consideration.

As further evidence of the use of stamps printed on cream paper being issued, used and cancelled in 1964, here are some 1/3d specimens concerning 2 blocks of 4, each clearly cancelled in 1964 that's been printed on a cream paper and alongside them, two pairs of the same denomination but printed on a white paper for comparison.

Here are the stamps as seen under normal light, note the date of the cancellations on the blocks "Chiswick 22nd of October 1964", "Littlehampton 6 lV? 1964" >

This is followed with an image of the same stamps as seen under long wave ultraviolet light. >

And finally the reversed image of the same stamps. >

It's up to you as to what you think, but the printing and issuing of cream papers for British stamps only up until 1962 as far as I am concerned is a complete fallacy, and needs to be rectified ASAP.

However, there could be a long wait involved before any changes are made in the SG part 3 specialised catalogue.
After sending various attachments a reply was made on 6th of September 2021 by Vince Cordell the new GB catalogue editor at Stanley Gibbons, he stated that the various differences that I have discovered "will be filed in readiness for consideration when we produce a new edition of the Spec. Vol.3 catalogue.
This will probably not be for at least five years, so it is as I'm sure you understand very low on my list of priorities at the present time.
Please keep me posted of further evidence "

So you could have a long wait before anything is rectified such as the contaminated, oxidized cream and fluorescent papers are concerned !

If you are looking for examples of a contaminated paper, then look no further than the 1991 greetings (good luck) stamp series, as I suspect that the whole issue was printed on this type of paper based on my findings. >

Here are some single used examples of what you can expect to find using a long wave ultraviolet light. >

It can be seen that they vary quite considerably, and based on all things being relevant, could it be that these particular stamps found without any fluorescent contaminants turn out to be quite scarce ?
(Food for thought)

After soaking off some of these 1991 greetings (good luck) stamps over the Christmas period I once more became aware of the fact that the fluorescent coating which covered these stamps was of a fugitive nature, leaving behind remnants on the patterned tissue I had used for drying them.
(See attachment) >

No doubt this was one of the reasons for a change of paper in 1992 along with the removal of the fluorescent contaminants !
WM

In retrospect I did mention that the new type of paper created in 1992 would solve the previous problems encountered in the past, but on inspecting some of the used 1993 Greetings (gift-giving) stamps (printed on this new type of paper) I have discovered variations to the contrary:
The 1993 Greetings set >

Here are 8 selected used copies as seen from the reverse >

Followed by the same stamps under L/W UV >

Then as seen in mono >

Seeing these variances with the naked eye gives a much better definition than the camera can capture, as the lighter coloured stamps are of a yellowish mustard colour, whilst the darker papers show up as a bluish grey/brown shade.
Therefore it's not just a couple of spelling mistakes that was made on the booklet covers such as Thomson with a 'p' and Sorrell with only one ' r ' that had to be rectified "twice" but also a different kind of paper was used in some instances as can be seen in the above attachments, of which should give them variety status.

From a batch of 37 soaked off, I only found 4 of the lighter mustard papers giving a ratio of around 9 to 1 in favour of the darker paper.

Due to the fact that my findings on several previous issues (including these 1993 greetings stamps) appear to be unrecorded at this point in time, I would therefore appreciate other members verifying some of the differences that I have discovered as being valid or otherwise ! Thank you.

Don't just take my word for it, check them out yourself !

Are there other stamp issues to be found with a difference on using this new type of paper ?

I previously exhibited some 2p PCP T2 (narrow value) stamps from sheets back in September of last year that depicted dark and fluorescent papers being printed on a contaminated paper, since then, I have discovered similar stamps of the 2p value that was produced for booklets also printed on a contaminated paper, seen below are a pair of such stamps, one with an imperforated left side the other being imperforated on the right.
The first attachment shows the pair as seen under long wave ultraviolet light >

The next attachment shows the same stamps but as seen under long wave ultraviolet, this time filtered into mono (seen in a different light) which promotes the enhancement relating to the contaminating fluorescent particles found within the embodiment of the paper. >

Once more giving another variety to the long list of missing varieties in specialised stamp catalogues.

These particular 2p stamps found to be printed on a contaminated paper originate from £1 booklets that comprised of 4 X 24p stamps and 2 X 2p ones plus 2 printed labels above that read "Please use the postcode", so therefore you will inevitably find some of the 24p stamps paper to be in a similar condition (contaminated) due to the fact that they were printed se-tenant.

Here is the actual format of that particular £1 booklet pane. >

Since finding many variations of paper on both the multiple crown Wilding issues and many of the earlier Machin stamps, I decided to have a look at some of the higher value castle stamps issued during the Machin period in 1992.
One particular value stood out from the rest, being that of the £1•50 value in relation to not just the paper but also the fluorescent ink that was used to print them.
Two types of paper seem to have been used, one being of a lighter shade and a scarcer darker shade was also found after checking through several hundred copies of this particular value under long wave ultraviolet light.

During the examination of these stamps I also noticed that two specific fluorescent coloured inks had been used to print these stamps, some examples that had been printed gave off an orange reflection under UV, but others appeared to be of a yellow/lime green shade when introduced to long wave UV, and more surprisingly both these coloured inks were found on each of the paper varieties.

The variation of the ink can be seen in the above attachment ↑
Here are two fine used pairs showing the same discrepancy.

Does this variation constitute a variety ? WM

Another thing that I noticed on inspecting these stamps was a slight variance in some of the shading found, just a few appeared to be of a more reddish nature when comparing them with the more regular ones which tended to be slightly brownish in appearance, I have taken a scan of the difference in order that you can see the variation of shade that was noted.

It's not in the magnitude of a 1935 Prussian blue difference, but nevertheless I think you will agree that there is a definite variation of shade to be found on some of these £1-50 stamps. WM

The difference in shade on the £1·50 Castle stamp has been known from when the stamps were issued.
Plate 2K was particularly affected.
Different shades occurred on the £2 1988 issue.
Harrisons acknowledged the differences but stated the shades were within the permitted tolerance limits.
Harrisons encountered many problems in printing this issue.

Thank you Lennox for the update given on visual shades to be found along with the £2 1988 issue.
Has there been any mention previously of the difference found relating to the inks response when seen under L/W UV such as the orange and yellowish ones portrayed in my previous attachments, or are they also another permitted tolerance ? WM.

I have a letter written by De La Rue regarding the Wilding Castle issue which is relevant.

“Stamp manufacturers look upon their product in an entirely different manner.
So long as we turn out a sheet of stamps which is correct to the naked eye we have done our job.”

Harrisons would not be concerned with differences that are only detectable under long wave UV.

From what the people at De La Rue have said then Lennox, is that they are not collectors of stamps or their varieties, but are predominantly printers of stamps and are therefore not concerned with other incidentals that may prevail, in other words they are not philatelists.
Fair enough, I can live with that !
As you are also a philatelist Lennox I think you will realise the differences that I have discovered in various papers and inks used by the printers as being varieties by using a long wave ultraviolet light irrespective of the naked eye. WM