My new stamp find!

I was going through my stamps, (again,) the other night... look what I found! A 14cent, 1978 issue cameo Queen Elizabeth that has a major printing error! woohoo... You can see that the error existed pre-mailing as the cancel goes right through it... now if I could only find someone to tell me if it's special?

canada stamp - 1 cent Cameo

Anyone into stamps who see this... is it an imperf? Anyone not into stamps... never mind! :)

*for those who've asked* this stamp was issued, perf 12, meaning 12 "holes" across the top where you'd rip it off the next stamp. This stamp has 15 and none on the left side. I think it was not perforated, not cut. It's ripped on the left side like someone had to tear it off.*