Anyone Else Seen This On #1898

Lower Left Corner block. Looks unused but mounted on paper . Third pic is under black light to show no smearing on tagging. Not sure about printing process but always thought the tagging was first. Looking for opinions.
Thanks

Look to me like someone drop a chemical on this....

looks like an ink smear over the tagging.

Robert

Chemically caused ink smeared over the tagging, as if not, the smear would be tagged also.

Happened after the fact.

So what came first..tagging or printing..?

Robert

1. Printing of stamp, including the word Canada
2. Tagging printed secong;u, with a secondary pass through the printing presses.
3. Smeared and smudged, by some unknown factor, possibly chemically related.
4. Photographed very well by a stamp collector.
5. Viewed by us'n, the viewers of the same.

I is rested.

I believe Puzzler is on the right track. May I suggest a chronology and simple cause:
1. Stamps were fully printed including the tagging.
2. The stamps are perforated, which slightly compressed the paper around the edges of the perf holes.
3. A post-production SCUFF that dragged some of the black ink downward and rubbed away some of the tagging except where it was protected by being on the slightly compressed paper around the perf holes.

As a narrative example, I could see this happening as part of the packinging and distribution operations to newly printed stamps (the ink and the tagging having slightly different drying and adhering properties to the paper) could have a poorly adjusted roller wheel smudge the fresh ink and the rub-off some of the tagging. Note also the marks are in parallel. I don't think there is a chemical factor involved. Just my 2 cents.

John Becker, thank you for the better description and correction.
Good to have the technically correct details all working.