[vector] sent in some of his other work, but I found his posts(part 1, part 2, part 3 and final thoughts) on check washing experiments pretty interesting. His results should be enough to make you think twice about writing checks. He tested a few different pens and tested them on real check using Acetone and Alcohol as solvents.
9 thoughts on “Check Washing Vulnerabilities”
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There are pens with ink designed to foil cheque washing, most notably the Uniball Signo 207 (recommended by a certain Mr K. Mitnick IIRC)
MacTech of EDCF did a comprehensive ink durability test here http://edcforums.com/index.php?topic=14009.0 though the images aren’t loading for me.
it’s a wonder you still use checks so much. i’ve never writen a check in my life.
either we pay, here in austria, with credit card, bank account card or cash of course. if the amount is so big you can’t handle it by one of the mentioned ways. bank transfer is a way…
i think checks do have some vulnerabilities that make them ‘dangerous’.
I hate checks the only time I use them is when I have to pay a bill to some company that is too archaic to use credit card, I also keep one in my wallet in case of emergency(it’s come in handy on more than one occasion).
In general though, I’m of the opinion that no purchase is too expensive to pay cash. I bought my last 3 cars cash. It’s amazing how persuasive you can be over the price of a car when you’re offering them a literal brick of hundred dollar bills as opposed to stupid amounts of paper work or waiting for a check to clear.
If you write with a fountain pen, “Noodlers Ink” makes several different inks that form chemical bonds with the cellulose in the paper and cannot be washed out. Some work better than others (“Bulletproof” Black is a good one)
Heh. I’ve gone through a single book of checks since I left high school, and I’m 28. My electric company (BGE) was too cheap to spring for credit-card processing, then they started to offer the “service” — through a 3rd-party processor who charged a ~$5 “convenience fee”. Fortunately, this year they got their shit together and started doing direct-debit on their website.
Other than that, I only use checks to send money through the mail to Amish people (not kidding).
It does seem like neither of the techniques tested (acetone or alcohol) was completely benign to the check. Acetone completely destroyed the security ink on the back, and alcohol changed the color of the background and left red spotting. Maybe a vigilant bank would notice such things. Then again, maybe not.
I’m a bank teller, and any of that discoloration or spotting would be noticeable immediately. We also have a device that shows us the embedded flecks of colors and such in checks using UV light. Most checks that come in are from local institutions, and seeing those so often, we’d notice a fake.
This is really old news.
Long ago someone I knew in sales confessed that they regularly microwaved checks for a few seconds before sending them out. He said that this erased the charge on the magnetic ink used for the computer-readable numbers at the bottom (MICR). The checks he wrote would take an inordinately long time to clear because they would have to be manually verified. These days I’m pretty sure it’s done optically though.