I was, as per usual, messing around last night and decided to have a look at the Zodiac letters and envelopes in varying degrees of tonal ranges and also reversed (makes some things easier to see).
I found this. Something my brain has always ignored and filed under, smudge, actually looks to be the number 5, from a stamp or something? Anyone know what that’s about and has it been mentioned before. I don’t recall if it has but now I’ve seen it it’s the most obvious thing on the page lol.
“I don’t know Chief, he’s very smart or very dumb.“
The more I look at that, I am seeing other words in there too Trav. Also, looks like a line or a bar running thru the 5, not sure if this is simply a result from you enhancing the photo or not
There is more than one way to lose your life to a killer
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The more I look at that, I am seeing other words in there too Trav. Also, looks like a line or a bar running thru the 5, not sure if this is simply a result from you enhancing the photo or not
Nah the bar isn’t really there, those are just jpeg artifacts from enlarging.
I have to remember that this was a POSTCARD as well as opposed to a LETTER so it was exposed, ie, sans envelope. I’m now wondering if it’s just something to do with postal markings.
“I don’t know Chief, he’s very smart or very dumb.“
I must be blind…lol. I don’t see anything. 
“…they may be dealing with one or more ersatz Zodiacs–other psychotics eager to get into the act, or perhaps even other murderers eager to lay their crimes at the real Zodiac’s doorstep.“ L.A. Times, 1969
I think the way he wrote the "Z" backwards might be a clue to Zodiac as well.
Ha!
Yes, that’s a ruddy great upside-down "5", yes, and that also looks like a hyphen, on what would be the same baseline, under "that".
Not a date stamp if it is a hyphen though. Too wide. Probably.
Very odd!
Nice spot Trav. 
Could it have something to do with a Watermark?
My two cents:
I see a five. I don’t see a bar. Like Wier, my first thought was watermark. However, I’ve never seen a cattywampus watermark and more than one should have shown up if it was, indeed, a watermark.
When in doubt, don’t.
Hi-
I have to agree that you have to be REALLY careful with artifacts. In 1998, when I first got interested in the case I made some really embarrassing errors thinking there were hidden clues in something in T17. I went back to the original source and it turned out that I was seeing things! I thought at first it was subliminal writing that hinted at Z’s involvement with the Bates case but…it was just plain old artifacts.
Mike
Mike Rodelli
Author, The Hunt for Zodiac; 3.9 stars on Amazon and
In The Shadow of Mt. Diablo: The Shocking True Identity of the Zodiac Killer, a second edition in print format. 4.3 Amazon stars and great Editorial reviews. Twitter:@mikerodelli
Yes artifacts are just like magic pictures.
There is definitely a 5 there though and I see what might be the hyphen, looks like it should be but I’m not sure. As for a watermark I don’t think so, this is a postcard afterall so it wouldn’t be possible to have a watermark due to the weight of the card.
Here’s another version of it floating around.
And just to add a visual reminder that this was a postcard and give some idea of scale.
“I don’t know Chief, he’s very smart or very dumb.“
