The purpose of this post is to try to shed some light on the subject of how to identify and distingush between these types of paper.
I want to emphasize that I am NOT an expert on Large Queens and I am still learning about these papers myself. I am fairly confident about my descriptions of all the paper types except for 7 and 9, which I may have backwards. I just see so few stamps on these papers that my descriptions here can only be taken as conjecture. I do not own an example of number 9, so I don't illustrate it here. However, I did once have an example and can describe it here. If you have an example and would like to send me a scan of the back, I would be delighted to add it to this article. I wanted to publish this now because I feel that an imperfect article is better than no article. I can at least up date it as more scans become available.
The Thin Papers - Duckworth Types 1 and 2
Duckworth Paper 1
Paper 2 as you can see has a softer appearance than does paper 1. Like paper 1, there is a translucent appearance, with a portion of the design being clearly visible through the paper. Paper two has a clear horizontal mesh pattern, as do papers 3, 4 and 10. What distinguishes paper 2 from the others though is that it is less than 0.003" thick when measured with a micrometer. This example here measures 0.0025".
Both of these papers are what the Scott and Unitrade catalogues are referring to when they list the stamps of this issue on thin paper.
The Normal Papers - Duckworth Papers 3 and 4
Duckworth Paper 3
The Laid Paper - Duckworth Paper 5
This paper has several distinguishing characteristics. The first are the horizontal lines that are visible, especially when the stamp is immersed in watermark fluid, as in the second photograph above. Another is the very smooth finish that shows no obvious mesh pattern. Finally, this paper is thicker than the other common papers, measuring 0.0035".
The Watermarked Bothwell Paper - Duckworth Paper 6
The distinguishing characteristic of this paper is the vertical striations that are very clearly visible, even without watermark fluid. Any watermarked stamps with the Bothwell watermark are on this paper. This paper is thicker than the other types, measuring between 0.003" and 0.004" thick.
Duckworth Paper 7 - The Ivory Thin Paper
The distinguising characteristic of this paper is how white it appears in comparison to papers 1, 2, 3, 4 and 6. There is some horizontal mesh, although it is much less obvious than in the other papers just mentioned. Finally, it is thin, just like papers 1 and 2, measuring 0.0025". It is a fairly scarce paper that is only found on the 1c, 2c, 6c and 12.5c values. At the present time, neither Scott or Unitrade list it separately.
Duckworth Paper 8 - The Soft White Blotting Paper
The key distinguishing characteristic of this paper is that it is opaque. It is this opacity that gives the illusion of the paper being thick. As a matter of fact, it is not any thicker than any of the other stout papers being between 0.003" and 0.0035" thick. Another characteristic is that it has no immediately visible grain. It is very soft to the touch and very white. It is actually similar to the thick carton paper found on the 15c value, but thinner. It creases quite easily, as it is a brittle paper and stamps printed on this paper often have short perforations or unpunched or incompletely punched perforations, with "confetti" adhering to the perforations.
Duckworth Paper 9a - Thin Tissue White
This paper is exceedingly rare, which is why I do not have an example to illustrate here. It's main characteristic is that it feels both extremely thin, white and resembles tissue paper in that there is no clearly discernible mesh pattern at all. The only other paper that is somewhat similar is paper 1, but the main difference between these two is that this paper is very white, just like types 7 and 9, wheras paper 1 is always toned. The second difference is that this is a very soft paper, whereas paper 1 is hard and crisp.
According to Unitrade, this paper is found on both 1c stamps and on the 6c. The only example I have seen that I had in my stock was on the 1/2c. I didn't know what it was at the time and wound up selling it to a knowledgeable collector who did for much less than I should have.
Duckworth Paper 10 - Smooth White Horizointal Wove
The Thick Soft Wove Paper
I found this paper on the half cent black and I believe that it is the thick, soft paper. Actually, it is quite rough in texture, but unlike the paper 1, it is not translucent and unlike the other Duckworth Papers, it does not show a clear mesh pattern. The thickness of this paper is between 0.0035" and 0.0045"thick, making it a full 0.001" thicker than the other normal Duckworth papers.
The scan below shows a side by side comparison of some of the types;
The above stamps are all 6c brown Large Queens. On the left we have paper 7, followed by papers 2, 10, 6 and finally 4.
That's my take on the Duckworth paper types. I would really appreciate any feedback that you care to give as I can then update this post with new information.