Withdrawal Dates For Decimal Machin Definitive Values

Hello all,

Values with a halfpenny aside, can I accurately assume that any given Machin decimal value remained valid and actively printed until it was replaced by a new colour or were some values simply not printed for periods?

e.g. the first 12p value appears to have been a lightish green, issued in 1980. A darker green 12p was issued in 1985. However, the 1984 definitive presentation pack, despite containing stamps issued before '84, has no 12p in it. Does this mean they stopped printing it between '80 and '84?

I can find issue date timelines online quite easily but no explicit mention of withdrawal/printing cessation timelines.

If anyone could direct me to an online source I would greatly appreciate it.

Thank you.

The halfpenny Machin values remained valid - they simply had to be used in tandem with another halfpenny value to enjoy their full total. eg 4 1/2p on its own would be 4p, but 4 1/2p + 5 1/2p would be 10p.

<<<<<https://en.wikipedia.org/wiki/Machin_series

<<<<<https://adminware.ca/machin?gt;>>>>

Peter

The decimal stamps without two-dimensional barcode remain valid until 31 July 2023.

https://www.royalmail.com/sending/barcoded-stamps