Canada #542, 552 6c & 7c Multicolored Computer Tape And Reel & Stylized 'BC', 1971 Census & British Columbia Centennial Issues, 16 VFNH Singles On Various HB, HB/LF, HB/F, HB/MF, HF/MF-fl, HF/LF & LF/DF Papers

16 VFNH singles of the 6c & 7c multicolored Computer Tape And Reel & Stylized 'BC' from the 1971 Census & British Columbia Centennial Issues on various HB, HB/LF, HB/F, HB/MF, HF/MF-fl, HF/LF & LF/DF papers. The lot contains:
• HB11 – wide & sparse (type c), medium & distributed (b) & small and high density (A) streaky gums
• HB10 – medium & distributed & small/high density streaks in gum
• HF9 – type A & B gum
• HB12/MF
• HB12/LF
• HB11/F
• HB11/LF
• HB10/F
• HB10/LF
• HF9/MF-fl, low density MF
• HF9/LF
• LF/DF

Unitrade values these at $4.8. The stamps offered here grade between 75 and 84 as follows:

Centering/Margins: 45/70, 50/70, 54/70

Paper Freshness: 5/5

Colour: 5/5

Impression: 5/5

Absence of Visible Paper Flaws: 5/5

Perforations: 10/10

This issue utilizes the same crisp HB translucent paper that was used on the Emily Carr issue and the Radio Canada International issue. On this issue we noticed three types of the spotty white gum, as shown in the picture. The types are distinguished by the density and spacing of the blemishes on the gum. The first type shows a very closely packed and dense parttern of blemishes. The second type, which is the most common, has the blemishes more widely spaced and the third type shows very few blemishes, or the blemishes being very widely spaced. The fact that this paper is always found with the spotty white gum does suggest that this paper may have been pre-gummed. The BC Centennial issue introduces a new type of chalk-surfaced paper, which shows no ribbing and tends to give a brighter fluorescent reaction on the front, as compared to the back. This is the type of paper that will be seen used on many issues from this point forward.

In describing fluorescence on these issues and all the stamps issued after 1970, it is critical to understand the Irwin-Freeman scale of fluorescence, which ranges from 0 to 12 and that a particular designation like say HB or HF will correspond to more than one fluorescence level. One pitfall that many collectors fall into is to compare the papers, rank the fluorescent reactions from low to high and then try to force them into the DF/LF/MF/HF and HB nomenclature, rather than recognizing that three different levels of reaction may actually correspond to the same designation. This is why Unitrade's listings for this period are so confusing. Generally HB corresponds to levels 10 through 12; HF, levels 8 and 9; MF, levels 7 and 6; F, level 5; LF, levels 3 and 4; DF, levels 1 and 2 and finally NF corresponds to 0.