I have gone through many different periods when it comes to correction pens. I guess I should start with the dilemma so you’ll understand where a bodek (examiner of tefillin and mezuzos) is coming from. The dilemma is like this: If I use a kolmus (feather pen), sooner or later I’m going to mess up an expensive set of tefillin. Then instead of earning a few dollars, I’m buying somebody a new set of parshios andthat’s not my idea of fun. If I use a Rapidograph pen filled with Dio (official safrus ink) I’m going to spend all my spear time sucking little bits of dried (bitter) ink and spitting them into the sink. If I use a Pilot G-Tec-C4 I’m hoping that there are no treif ingredients in the ink. Since it is made in some very far away nation, Pilot will not reveal the contents to me. I heard rumors that Israeli Soferim checked it out, but who knows what that really means. Now the Pilot has some real advantages. For one, they only cost a few dollars apiece, so I can afford to lose, break, and give them away to aspiring soferim. And they make a precise dot of ink exactly where you want it. You can still mess up if you don’t know what you are doing, or even if you do know what you are doing but you are in a rush, but safety-wise they are about as good as it gets. Now here is where the story gets exciting. Rabbi Daniel Melamed told me about a kind of rapidograph that although I had seen it, I had never experimented with it. It’s the Rotring Rapidoliner size .25mm. Of course two days latter I was at Pearl Paint in Peramus, NJ checking it out. Not being able to read the Swiss or German (or whatever they were) directions, I was left to my own common sense to figure it out. Having played around with more than a few pens in my efforts to discover the perfect correction pen, I studied it, determined that it looked promising, and took a $17.91 chance. So far I must say I am impressed, but it hasn’t had too much time to get clogged up. I can tell you that it puts a nice small drop of ink exactly where I want it, and it seems to flow without too much kvetching (not like Kohiner Rapidographs that clog like every two seconds–literally–you have to shake them every few seconds that they are not in use or the ink won’t flow). Of course the biggest advantage is that I filled it with real old-fashioned dio! The first modification that I did was to put a small pocket clip on the pen side (as opposed to the top side where they are normally found). This was done to keep the pen from rolling of the table and destroying the fragile point in the fall.
Update: I’ve been using the Rotring for two weeks, and as long as I dab the pen on my tongue after each use (even if I only use it for a drop of dio), the moisture from my tongue keeps the pen from cloging. Of course if you don’t like the taste of dio (and I’m not quite sure why you wouldn’t (can you say, “Tannic acid”?) you could always dip it into some conveniently placed cup of water.