Canada #660vi 8c Multicoloured, Marguerite Bourgeoys, 1975 Authors Issue, A VFNH UL Inscription Block of the "Red Thumb" Variety on DF Smooth Paper
A VFNH upper left inscription block of the 8c Marguerite Bourgeoys stamp from the 1975 Authors issue, showing the "red thumb" variety from position 11 in some sheets. Printed on the dull fluorescent smooth paper. This is much scarcer than the horizontally ribbed paper, which we offered as a single some weeks ago.
Unitrade values this block at $50. The stamp offered here grades 75 as follows:
Paper freshness: 5/5
Absence of visible paper flaws: 5/5
A General Note About Constant Varieties on Lithographed and Photogravure Issues of This Period:
Stamps from the period prior to 1972 were often printed in layouts of 200 or 300 stamps, divided into either 4 or 6 panes of 50, or 400-600 stamps divided into 4 or 6 panes of 100, for the smaller stamps. However, when Ashton Potter took over printing most new issues, the printing layouts were different for most stamp issues, and little is known about the specifics, because Ashton Potter was a private company.
What is understood is that the constant plate varieties found on these issues often do not occur on every pane, but sometimes just once in every 3 or 4 panes. This applies to the few constant tagging varieties that exist as well.
A good guide for judging scarcity is to look at the catalogue value. Generally any variety listing for under $5 is found on most every sheet, or every second sheet. Varieties listing for $5 or more may occur once every 3-4 sheets and varieties listing for over $20 will occur very infrequently, i.e. once in every 4 or 6 panes. Remember if a variety is only found once in 6 sheets, that means you have a 1:300 chance of finding one if you search a random selection of unpicked mint stamps. I find that this places the catalogue values in better perspective. Unitrade places an "EP" notation next to any variety that is found on every pane of 50 as well.