[Editor's Note: This question was submitted via email.]

I hand write many, many checks daily in my business. I am looking writing pens(ink) that will be tamper-proof once the check is written.

I am not sure if there is such a thing as "tamper-proof" ink. Some inks are more resistant to tampering than others.

Ballpoint pen ink seems to be one of the most vulnerable to "washing" where a criminal will use chemicals to erase part or all of what is written on a check (other than the signature!) in order to write in a new payee, date, dollar amount, etc.

I have HEARD (not having tried to wash a check myself!), than felt pen and gel pen ink is more resistant to washing.

If you have a concern about someone tampering with your check, you may try doing the following:

- Apply heavier pressure when you write. While ink may be washed, the depression in the paper will not go away.

- Fill in all the spaces on your check. Do not simply put numbers for the date, but write in the month and fill in as much of the line as you can. If the payees name does not fill the payee line, then write a squiggly line after the name deter someone from altering the payee name. The same goes for the written dollar amount - write the squiggly line to deter someone from "upping" your amount. When you write the numerical amount, write large enough to deter someone from adding "zeros" to your amount.

- Use a color that is not as common - such as a purple, red, or teal color.

While there are some computer ink's available for printing your business checks, I also have not heard of an ink pen that would fit the bill.

One way that check companies and banks have tried to combat washing is to use paperstock which is resistant, or shows obvious changes in the stock when washed. Not all check producing firms use this stock, but many do. When washed it basically discolors the entire items, making it obvious that the item has been tampered with.

I am an advocate of writing checks with felt-tip pens, for the reasons that Bonnie mentioned. another advantage to using felt-tips is that the ink actually 'soaks in' to the paper, rather than just sittting on it like ballpoint ink does.

In addition to the tips mentioned here, if you have concerns that your checks may be altered, I also suggest that you ask your bank if they offer positive pay service. In a nutshell, positive pay is a service through which you would give the bank a file which indicates the checks you've written (at least by number, date, and amount,) and all checks clearing against your account are compared to this file. If something doesn't match, then the positive pay system automatically rejects the item for additional verification.

If this is not available to you, use the bank's telephone or online banking to verify the checks that have cleared your account. By doing this daily, you will at least be able to pick up on altered amounts (and altered payees, if the online banking includes check images) and notify the bank promptly.

From an item processing and imaging standpoint, stick to permanent black felt tip pens. This will provide you the most protection. Gel pens and other colors do not image well and will cause you problems if you ever need a clear copy of the check from the bank.