Due to unforeseen circumstances regarding family matters, I had to bring everything to a halt once again. The book I have been writing has taken a bit longer than I would like due to those circumstances and since I know a lot of members are patiently waiting I thought I would give you guys a snippet from my book regarding master die doubling.
For every 2003-P, 2004-P, and 2005-P minted for circulation with the new effigy of the queen, all feature master die doubling.
When comparing to the new effigy on 2003, 2004 and the 2005 copper-plated zinc cents you will notice that this master die doubling is not present.

Although master die doubling is not rare and extremely common for these years, it is something not very many collectors actually knew were there in the first place.
My book is exclusively about Doubled Dies and not master die doubling, however since there are ALOT of master die doubling examples spread out across all 7 denominations and numerous dates, I felt that I had to make sure readers knew exactly what is a Genuine Doubled Die compared to Common Master Die Doubling.
Finding and discovering modern Canadian doubled die varieties since 2018.
2023 Recent Publications:
Modern Canadian Doubled Die Varieties - First Edition
PDF & Paperback
https://www.mcddv.ca (website currently down for maintenance as of 08/01/2024)