For the interested, a little more background on the Canadian Issues.
In 1915 a Special War Tax Revenue Act was passed in parliament. Among the taxes was a levy of one cent applied to most letters and postcards. Special stamps were to be issued for paying this tax but where they were not available, regular stamps of the higher denomination could be used.
Two designs were used and, unlike most countries which overprinted the words "War Tax" on regular postage, these were engraved into existing stamp designs. In all cases, the "Admiral Issue" of King George V was used.
The first type engraved a two line inscription in white lettering on to the lower part of the stamp. This was used on the One Cent green and the Two Cent red. The second type used the symbols "1Tc" in colorless writing, in two dies, on the Three Cent carmine. Coil stamps, perf 8 vertical, were also issued.
Late in 1916, a supply of this stamp came out perf 8 x 12. The stamp had been prepared as a perf 8 coil but was reperfed 12, horizontally, to fill an emergency need for the Three Cent value.
Public complaints about the similarity between the former Two Cent and new Three Cent stamp led to a colour change of the latter to brown.
A third type of War Tax stamp exists though it was not intended for postage but as a revenue stamp to pay the War Tax on wines and spirits. This is a War Tax overprint in black on the Five Cent and Twenty Cent values and in red on the Fifty Cent value. Though rare, they were accepted for postal use and can be found on cover.
Below are the 7 (or 10) War Tax Stamps of Canada.







