Gifts From The Wise Men - 444p

This mint stamp is different from what I'm used to seeing and wonder if anyone can explain why it looks this way. It's the 5 cent 444p Christmas stamp, Winnipeg two bar, of October 13, 1965. The tagging seems either very dark or very thick as noted by the face and reverse scans. The centre untagged portion appears similar in the white shading colour to the untagged stamp, also scanned for comparison. The light vertical lines along the inside edges of the tagging on the front of the stamp almost suggests a double paper, but only where the tagging is, and close inspection shows that this is not the case. All scans are exactly as they appear to the naked eye.