Make your own magnetic ink

Here [Catarina Mota] is showing off a ring of magnetic ink printed on a piece of paper. It’s strong enough to hold a disc magnet in place when the paper is raised vertically. This strength comes from mixing your own batch of ink.

Magnetic ink has been around a long time and is most often used in banking. The account number and routing number on the bottom left of paper checks are printed in magnetic ink to allow for automated recognition. Iron oxide is charged by the reader as it passes through. In this case, magnetite is used as the doping agent as it has very strong ferromagnetic properties. By mixing it with acrylic medium in a vortex mixer you end up with a homogeneous ink.

There’s a quick demo after the break that shows how well this printed ring holds the magnet. What are some things for which you would use this ink? Leave a comment to let us know.

http://vimeo.com/4435340

[via Make]

Comments

  1. BinaryGangster says:

    Correct Vimeo link: vimeo(DOT)com/44353407

  2. Thomas says:

    Unfortunately the Video link is not working anymore.

  3. LongFist says:

    Would be really interested in discovering whether or not this ink could be encoded, exactly as a magstrip. If so, it becomes really interesting to employ in machine-based operations — like a barcode that only the machine can read. And – here’s the fun part – you can then conceal its presence by the creative application of black paint, leaving competitors scratching their heads trying to figure out how your machine “does it”.

  4. J Harton says:

    It’d be funny to have home made floppy disks if you could make it work. Probably take a lot of testing, though. You’d need film to paint the ink onto probably though, and have to determine how tracks were made. Could be fun if only to do something that might work.

  5. Hirudinea says:

    I once found a toy in the Goodwill that played cards with a small mag stripe on the bottom to answer trivia questions printed on the card, I made replacement cards with some cassette tape glued to 3X5 cards but the tape kept falling off (crappy glue), this would be ideal to make new cards. Also you could make “talking” post cards by putting a stripe on your post card, writing it with a modified Iphone card reader and your friend can read it with the same thing, retro!

  6. Comments says:

    I dunno why no-one linked to the original site…

    http://openmaterials.org/2012/07/02/diy-magnetic-ink/

  7. Flash/Adobe hater says:

    Hmm, find a way to mix it with thermite and you’ve got an awesome
    opening scene for the next Mission Impossible film.

  8. Anka06 says:

    Great lesson…

  9. vic says:

    Nice. Paint a wall with it and then cover it with normal paint and you’ve got a whole wall to stick notes on or whatnot. Or use magnets instead of thumbtacks to attach posters.

  10. Yes! Finally someone writes about webseiten erstellen.

  11. Sherman says:

    t get too much direct heat during the cooking process.

    The grill unfortunately is a risky place to cook meals,
    and also the griddle can be a great present
    towards the wellbeing aware. There is also the question about whether
    to use a pizza stone, ceramic tile, or the pizza screen.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 96,687 other followers