Author Topic: Id help for Concentric Paperweight  (Read 1525 times)

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Offline tropdevin

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Re: Id help for Concentric Paperweight
« Reply #10 on: January 26, 2012, 10:01:57 AM »
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Hi Roger


You have hit the nail on the head when you say ‘I am odd with colours’.  That is one of the several majors problems with UV fluorescence as a diagnostic tool – different people see colours in different ways; it is a subjective assessment.  I disagree with my wife about what is blue or what is green when we get to colours near ‘turquoise’.  So descriptions such as ‘pale straw with a hint of pink’ are probably more appropriate to the catwalk than to paperweight attribution.  There are some significant differences between paperweights that most people would agree on, but you have to be very careful with interpretation.

The best way to study fluorescence would be to get a source of precisely known wavelength(s) – not just from some ‘black light’ made for security, philately, or mineraology – and a spectrometer to allow quantitative measurement of frequency and intensity of fluorescence.  But that is beyond most - if not all – collectors, unless they work in a relevant research lab.

Much detailed scientific work on fluorescence was carried out by an American professor (Woldemar Weyl) in the 1960s for the glass industry.  He found that the glass composition and trace elements affected fluorescence – as one would expect – but that other factors such as the annealing process and the gas composition in the glory hole also affected it.  I recall a paperweight meeting at which Dave Moir brought along several one-off weights he had made at Strathearn – the results of the UV tests led him to be assured that they had been made at more than one factory, whereas the UV differences were probably a result of variations in the manufacturing process.

One paperweight book says (and it gets repeated as if true) that most antique Saint-Louis weights fluoresce ‘coral pink’.  Mine don’t – but that probably means we used slightly different illumination for the tests.    I remain to be convinced that many of the results of UV testing are meaningful.

Alan
Alan
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Offline KevinH

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Re: Id help for Concentric Paperweight
« Reply #11 on: January 26, 2012, 06:33:24 PM »
Roger, thanks for your confirmation about having both longwave and shortwave uv lights. The "pink" part of your "light green with a hint of pink" may be a result of reflection of the glow of the uv bulb!

And thanks to Alan for the comments about problems with uv analyses, for which I will add something below.

However, your "lght green (smoky)" could tie in with what I see as "dusty grey". If that is true then I am happy enough that your weight is not from Vasart Ltd (i.e. 1956-64) or Strathearn (1964-80). Are you able to adequately separate "greens" and "blues"? If so, the quite strong blue under shortwave uv of Vasart Ltd & Strathearn would be clearly noted. If that is not the case for your weight then I would say it is not from those factories.

But in my experience, weights from the Moncrieff and Ysart Brothers factories have pretty much the same longwave reaction and also much the same for shortwave reaction. So it cannot be said that uv reaction can specifically indicate Moncrieff, as it could equally be Ysart Brothers (or even other factories, UK and elsewhere).

I have found that although difficulties occur with assessment of many uv reactions, in a number of cases the reactions are so different as to be a good indicator even if the actual colour or shade is not always easy to determine, or to agree person to person. It is the clear differences that help to a large extent with Ysart and similar weights. And it is the clear differences, not the alterantives in shades of colour, that I use to determine the likelihood of a Vasart Ltd or Strathearn weight as opposed to one made at the Moncrieff or Ysart Brothers works.

Alan is quite right that there are many difficulties with uv analyses. In 1969, Paul Hollister Jr. warned about the problem in his book, The Encyclopedia of Glass Paperweights where he commented on different colours seen for weights from known factories, whereas various people had assumed certain colours meant certain factories (such as "Pink / Peach" for St Louis). At that time the analyses were done with only longwave uv., but in the book, the actual wavelength was not stated (as far as I can see), nor details of the type of lamp used.

For the record, all of my analyses of Ysart and similar weights have been done with a mains operated unit (230 volt, used with UK 240 volt system) and having dual bulbs, longwave (365 Nm) and shortwave (254 Nm).

Another point that Hollister made was that, as an artist, he was well aware of the effect that one colour could have on an adjecent colour. Without going into detail, I can confirm that when I photographed weights under uv light, using one weight as a standard control with the analysed weight adjacent to the control, I occasionally noted that the control weight showed as a noticeably different shade! Hollister's comment may well expalin this.
KevinH


Offline Roger H

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Re: Id help for Concentric Paperweight
« Reply #12 on: January 26, 2012, 11:17:54 PM »
  Interesting and complex subject. See what you mean I think, if kept to the main definite colours it can be very useful for ID but if taken to shades of colours it could be misleading because of other factors needing to be in the equation, like uv light type, the persons perception of colours, surrounding colours and so on.
       My wife often says "its reflecting off the colours in the weight also".
   I can differenciate quite easily between blue and green but when it gets to turquoise then it becomes difficult to agree with my wife on the colour. Even some blues I can see a warm blue which means to me it has 1 or 2% red in the mix.
        Last time I looked Simons weight was doing quite well on the auction, I'll have a look in a minute. Will say simons weight is better made than mine, but I like the orange crunchie base colour in mine.
                Roger( the revisionist).


Offline Roger H

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Re: Id help for Concentric Paperweight
« Reply #13 on: January 29, 2012, 10:10:06 PM »
   Well somebody bought it at all costs, its a nice weight but it would have to be signed and dated for that price for me. Would anybody like to buy one similar with an orange crunchie ground?????????????????????????
         Roger (the realist).


Offline SimonD

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Re: Id help for Concentric Paperweight
« Reply #14 on: February 12, 2012, 02:23:38 PM »
I have a Paul Ysart scramble paperweight which has a not too dissimilar bubbly ground...


Offline KevinH

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Re: Id help for Concentric Paperweight
« Reply #15 on: February 12, 2012, 05:19:12 PM »
Simon, why do you belive the scramble weight is one of Paul's?
KevinH


Offline SimonD

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Re: Id help for Concentric Paperweight
« Reply #16 on: February 13, 2012, 08:47:49 PM »
Hi Kevin - I think my scramble weight is by Paul largely because its similar design is similar to those ascribed to Paul in books. I haven't been able to cane match, but no canes immediately jumped out to me as Salvador canes, or even Ysart Brothers. (I've handled a Salvador/YB scramble in the past, and it was very different.)

Here are a few more photos


Offline KevinH

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Re: Id help for Concentric Paperweight
« Reply #17 on: February 14, 2012, 12:12:08 AM »
Thanks for the additional photos, Simon. I agree - no "Salvador canes" that I can see, so I agree it's one of Paul's.

The yellow ground does show some bubbles (holes), which is something I hardly see at all in my own PY weights. But the bubbles/holes are not as extensive as in Roger's (*) example.

(*) I suppose I should now say "my example" as it was me who pressed the button on Roger's eBay listing.
KevinH


Offline KevinH

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Re: Id help for Concentric Paperweight
« Reply #18 on: February 14, 2012, 12:30:05 AM »
And now that I have the weight that Roger showed, I can add a photo of it against another "holed-ground" weight I have. The weight shown against the ex-Roger one has an orange ground almost the exact shade of the other and although it does not show too many obvious holes from the top view, the oblique view photo does make it clear.

The canes in the "Catherine wheel" design weight can all be matched to other Salvador / Ysart Brothers work and the design has been seen in at least three Inkwells of the typical Salvador/Vasart type and at least two other weights. (That design, however, was not generally known until a few years ago when all the items seemed to almost appear at once! But they are all genuine, so no worries there.)

I have also added another weight with a bubbled/holed orange ground (albeit a much darker orange). This, of course, is a Roundels design and having no outer cane between the roundels is a Salvador version.

From this evidence, I vote strongly for Salvador Ysart as the maker of the ex-Roger weight and also of Simon's weight which kicked off this thread. ... Oh, and one other thing ...
KevinH


Offline KevinH

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Re: Id help for Concentric Paperweight
« Reply #19 on: February 14, 2012, 12:47:52 AM »
... I will now admit to having a weight that I have not shown publicly since I bought it. It came from the USA, via eBay some years back. From the top view, it shows basically the same pattern as in Simon's and the ex-Roger weight. But check out the side view - it is the only one I have seen like it! I have been waiting for something similar to appear but so far it has not.

Perhaps this domed example was a forerunner to the standard millefiori version of that pattern. Or maybe it was just a whimsical variation at much the same time as, or even later than, the others?

The canes in the outer row have suffered a lot of movement in the section shown in the side view photo. The large central (top) cane is one of the so-called Salvador ones. The yellow cane with black centre is an example of those found in items by both Paul and Salvador. The powdered green element is unusual as it is used solely as a "side" decoration - the actual regular ground is a very powdery looking white.

The pontil scar does tend much more towards Salvador as the maker and the powdery white ground adds to that as, so far, I have not seen it used by Paul but it is known in several pieces by Salvador, including an Inkwell that was very recently sold on eBay.
KevinH

 

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