Great Britain SC#354fp SG#611n 1d Ultramarine & 3d Deep Purple Queen Elizabeth II, 1960-1967 Wilding Issue, Phosphor Tagged Issue, Se-Tenant Booklet Pane of 4, Violet Phosphor, 2 Bands on Each Stamp, HF Paper, Sideways Inverted Watermark, VFNH

A very fine mint NH se-tenant booklet pane of 4 of the 1d ultramarine & 3d deep purple Queen Elizabeth II stamps from the Multiple crown sideways watermark on fluorescent white paper. Although not listed in Gibbons Specialized both the cream and white papers on the multiple crown watermark can be found with wide differences in fluorescence when viewed under long-wave UV light. The cream papers generally are either non-fluorescent or dull fluorescent with fluorescent flecks that make the paper appear LF. The white papers exhibit a much broader range, from dull fluorescent all the way to hibrite, with many of the fluorescent papers having fluorescent flecks of varying concentrations and brightness levels in the paper. Phosphor bands reacting violet under short wave UV light. On this issue, there are three colours of phosphor bands, depending on when the stamps were issued. The first phosphors used between 1959 and 1961 gave a green afterglow under short wave UV light. These were replaced in 1961 by a chemical giving a blue reaction under short wave UV light. These were replaced in 1965 by a violet phosphor, which was initially applied in 8 mm bands, and later 9.5 mm bands. Gibbons values this at £10. This translates to approximately $20. The booklet pane offered here grades 75.

We have written a post that gives a good overview of this issue, explaining how the different varieties fit into the whole. The post identifies the key points of interest and explains how you can turn it into a super specialized collection. You can access that post here.