|The subject of paper fluorescence is confusing because many of the papers used contain fibres in varying densities that react differently to the UV lamp than the main paper. In addition, the use of paper coatings in the early 1970's has resulted in many papers that give different reactions on the face of the paper from the back. |
To begin with it is important to understand the basic levels of fluorescence and what they look like:
1. Dead paper (Dead)
2. Non-Flourescent (NF)
3. Dull Fluorescent (DF)
4. Low Fluorescent (LF)
5. Medium Fluorescent (MF)
6. High Fluorescent (HF)
7. Hibrite (HB)
Dead paper appears either a dark brown or a very dark purple under the UV lamp. There is no bluish white or white glow whatsoever. This paper absorbs light and reflects none. True dead paper prior to the early 1990's is rarely seen. Much more common is NF paper.
NF paper appears a lighter brown or lighter purple. Again it absorbs and does not really give off any glow at all. The main difference between NF and dead paper is in the depth of colour that the viewer sees.
DF paper is the most common paper type prior to the Centennial issue. This paper type varies quite a bit in colour under UV, but generally, it gives off a very dull, bluish or greyish white appearance. It will not have the brownish or violet appearance of the NF or dead papers. It will not appear to be at all fluorescent, but compared to the above 2 types it looks quite fluorescent.
LF paper give off an unmistakable light bluish white glow under UV. Generally it can be quite bluish.
MF paper gives off a brighter, lighter bluish white glow.
HF Paper is very bright, but less so than the hibrite. There will still be a slight hint of blue or violet to the light.
Hibrite paper is unmistakable in the sense that the glow is almost pure, bright white.
What complicates the picture is that in addition to the basic grade of the paper, there are often found, fibres which show a different level of fluorescence. These fibres can be very dense, to the point where you can barely see individual fibres, right down to very sparse, there there are only 1 or 2 fibres visible on the stamp. Often these fibres can fool collectors into thinking that a paper is more fluorescent than it actually is.
My listings will therefore adopt the following naming convention:
NF - HBFl - VD/ LF - HBfl - VD
The initials in front of the slash represent the reading of the stamp from the front and to the right of the slash the reading from the back. Where there is no slash and only one reading then it means that there is no difference between the front and back readings.
The initials in front give the basic fluorescence grade of the paper, followed by the brightness of any flecks or fibres, followed by their relative density. In the above example, the paper would be described as:
Non-fluorescent paper on the face, showing a very dense concentration of hibrite fibres. On the back the paper appears the same way, only the overall fluorescence level is low, instead of NF.
In terms of fibre densities the following are used:
VVS - very very sparse - 1-2 fibres per stamp.
VS - very sparse - 3-10 fibres per stamp
S - stamp is covered with fibres that are all fairly spread out.
LD - stamp is covered, but the fibres are closer together
MD - stamp is covered and the fibres are all fairly close together and dense.
HD - the concentration is so thick that it is difficult to see individual fibres.
There also exists a chalk-surfaced paper during the 1972-1976 period which comes with either a smooth surface, a distinct vertical ribbed surface and a distinct horizontal ribbed surface. The reactions of this paper under UV light are quite varied, but there is a DF paper which shows very clear woodpulp fibres on the back under UV. The descriptions of these stamps will include the word "woodpulp" after the initials describing the paper fluorescence.
Hopefully this will make the descriptions in the catalogue less confusing. One of the annoying problems that collectors relying on the Unitrade catalogue is the lack of descriptions for each level of fluorescence, coupled with the fact that the same level of fluorescence is rated differently from one issue to the next. In my listings, I will attempt to relate my fluorescent grades back to what I think Unitrade is referring to, and will adopt their numbering system.