Leopold Beaudet has suggested that the 5c violet LL corner block, like the 1c yellow and 2c green with type B lathework, may represent trial printings made to demonstrate the colour change before regular production began. His argument is plausible because the plates used for these items appear to have been obsolete by the time the changed colours were issued. In the case of the 5c violet, the block comes from a design type 3 plate in the 11–14 group, yet the first recorded 5c violet plates, 15–16, were approved on 19 November 1921 and the stamp was issued on 2 February 1922. If new plates were already ready, it is hard to explain why ABN would have reverted to earlier plates for the first violet printing unless the material was prepared as a colour trial rather than for normal production.

This newly recorded constant plate variety strengthens the link between the blue and violet printings from the same plate group and helps refine this hypothesis. The same characteristic pair of almost horizontal lines in the upper left margin opposite the “N” of CANADA has now been found on both the 5c blue and the 5c violet, indicating that at least one design type 3 plate—quite possibly plates 13 and 14—was used to print both colours. This supports the view that an earlier plate was carried forward into the violet period, but the continuing absence of plate imprint material or other multiple examples from plates 11–14 in violet suggests that such use was limited and more consistent with a colour trial than with routine production.

Beaudet also notes that the existence of a used 5c violet from plates 11–14 does not in itself disprove the trial‑printing hypothesis, since used examples are known from other trial printings, such as the 2c green with type B lathework. At the same time, aside from the LL corner block and this small group of used stamps, no 5c violet examples from a plate earlier than 15 have been reported, especially no plate imprint pieces. Taken together with the parallel cases of the 1c yellow and 2c green with type B lathework—both printed from plates that were already obsolete when the new colour was issued—the emerging evidence is still most consistent with Beaudet’s view that the 5c violet material from plates 11–14 represents a restricted colour trial from an older plate, rather than full‑scale production.

(This note summarizes points developed in our email discussions.)