The GB 1912-24 Halfpenny

The KGV Royal Cypher ½d Value
Just this one stamp fills an entire album

The Shades. There was a wide range of shades, especially during wartime when some inks were difficult to source. There a pale greens, deep green, yellow-greens (including the very rare Cyprus green), blue-greens, etc. The simplified catalogues list all of these in a single entry as 'green'. The Stanley Gibbons GB Concise catalogue lists 6 shades sg351-356. Their specialised catalogue lists 18 shades. In reality, there are many more - as this collection shows.
Varieties There are watermark variations, Specimen and Cancelled overprints and many plate varieties and printing errors.
The Controls. The bottom margins of the sheets had a control number under the second stamp such a 'G15'. The numbers indicated the year of printing. These too form an interesting study. This lower margins is either imperf or perforated through.
Plating Study The printers made various markings in the marginal rules. These can be used to identify the plate from with that sheet was printed. The pages of this section were taken with a camera that did not have its claimed resolution. The details and colour representation are not good. These will be replaced with scans when time permits.

The shades varied - particularly during wartime when inks were difficult to source