This stamp has a hidden date in the bottom-left corner. It is hidden in the three lines that run above the word "CANADA".
This stamp displays the designer's initial. The initial H belongs to Emanuel Otto Hahn.
The 4¢ postage stamp reproduced, displays a sculptured profile of Her Majesty will be issued to commemorate Her Coronation. The design for the Coronation issue stamp was created by Emanuel Hahn, R.C.A., S.S.C., a sculptor of Toronto, Ontario.