Lot #37 Canada #BK66a 1c Purple Brown, 3c Slate Purple, And 7c Slate Green, 1967-1973 Centennial Issue, A Specialized Lot of Two 25c Booklets Containing One Pane of 5 Plus Label, Type 1 Free Dispenser Cover, Black Seal Strip, Different LF-fl Papers

An interesting group of two complete 25c booklets, each containing a pane of 5 plus label of the 1c purple brown Northern Lights and Dogsled Team, 3c slate purple Combine and Rig and 7c slate green and emerald Transportation stamps from the 1967-1973 Centennial issue, with type 1 "Free Dispenser" covers that have a black sealing strip. Printed on different low fluorescent papers as follows:

• Vertical ribbed LF-fl with sparse concentration of LF fibres and very sparse concentration of MF fibres, 7c stamps are the slate-green shade.
• Vertical ribbed LF-fl with sparse concentration of LF and MF fibres and sparse concentration of brownish woodpulp fibres, 7c stamps are the emerald shade.

Although Unitrade, McCann and Harris list LF paper, there are several variations of this paper. All give a bluish to bluish white glow under UV, but the papers contain different concentratons of LF and MF fibres, which make the paper appear brighter, as well as different concentrations of brownish woodpulp fibres, which counterct the fluorescence, making the paper appear duller. All of the papers on BK66 and BK68 are vertically ribbed.

The 1c, 3c and 7c booklet stamps printed by BABN were printed in at least two shades:

• The 1c stamps are found in purple brown and violet brown shades.
• The 3c stamps are found in slate purple and blackish violet.
• The 7c stamps are found in emerald and slate green.

The gum used on these booklets is a white PVA with an eggshell sheen.

Unitrade values these booklets at $12, counting them as basic varieties. The booklets are all VF, grading between 75 and 80.