need to find out how to make it . required for reading checks
To insinuate that someone wants to or is looking to pursue this for criminal purposes is kind of calling the kettle black. I have a business and do my own payroll so MICR ink is outrageous and the guy that invented the little chip that tells you to replace the cartridge? now that is criminal..there is nothing wrong with a small business saving money if possible
No, MICR ink is not required for reading checks, it is required for making checks. Perhaps you should go and read the answers to your previous question.
There's an Instructable for making ferrofluid which uses old backup tapes, acetone and vegetable oil HERE.
If you want something you can forge checks with, it would probably be best to go with the professionally made MICR ink. You can read about it here:http://en.wikipedia.org/wiki/Magnetic_ink_character_recognition And you can probably buy it on eBayhttp://shop.ebay.com/i.html?_kw=micr&_kw=ink If you really, really, want to synthesize some magnetic nanoparticles in a colloidal suspension in an organic fluid like oil, or ink, I have seen recipes for this too. E.g.http://www.chemhacker.com/2010/04/homebrew-ferrofluid-synthesis-introduction/ As mentioned in the introduction in this article there is a big difference between a true colloidal suspension of magnetic nanoparticles, and something less sophisticated like iron fillings mixed with oil. The difference being that a true colloidal suspension does not settle out, does not become unmixed, the way a simple mixture does.
Another ferrofluid how-to. This one has lots of pictures, and uses common rust instead of ferric chloride.http://opensourcenano.net/projects/project1/
So...your previous question wasn't answered well enough?