The $20 carries the most remarkable portrait in the series: Princess Elizabeth, aged eight, engraved from a 1934 Marcus Adams photograph - the future Queen Elizabeth II on a banknote seventeen years before her accession. The English printing split into two varieties, and this is the scarce one: 200,000 notes with the large seal of the Bank of Canada before the die changed, against 802,700 with the small seal.
The variety carries serious money in high grade. A Large Seal with serial A000008, certified CUNC-64, brought $63,840 CAD at the January 2020 FUN show, and a GUNC-66 example reached $49,300 CAD at Torex in 2019. The seal is the difference, so the seal is what to verify - and what a mislabeled listing quietly gets wrong.
The child-Queen twenty is the series' best crossover note, pulling royal collectors who own nothing else Canadian. Between the two seals, buy the attribution, not the adjective: a certified holder that names Large Seal is worth more than a seller's opinion that the seal looks big.
Mintage figures: United States Mint (Annual Report of the Director of the Mint), Royal Canadian Mint records, and — for the 1935 banknote issue — Bank of Canada printage records as published in the Charlton Standard Catalogue of Canadian Government Paper Money, cross-checked across independent published references. Specifications: United States Mint coin specifications.