The multi-pen is the
Swiss Army Knife of the pen world. It is a type of
writing instrument that has more than one mode of writing. It typically includes a blend of multiple colors of
ballpoint pens, multiple thicknesses of
pencil lead, or a
stylus. Usually there are three to four “
points,” though more than a few have only two. Some
novelty ballpoints have ten or more.
The multi-pen most of us first encountered is made by Bic. Four buttons extend a different color of ink (red, blue, black, and green). Hitting a different button retracts the point that is extended, replacing it with the new color. Hitting the button halfway retracts the point completely, making it safe for a pocket.
Several other companies make nice multi-pens. rotring probably has one of the best. All have one button at the top. Depending on how you are holding the pen, a different point comes out (based on which icon that is up). Either a twist or hitting a different button (usually built into the clip) retracts the point. The rotring 600 is the top of the line, with a 0.7 mm pencil and red and blue ballpoints. Others have three thicknesses of pencil lead, or have added a stylus or highlighter.
Lamy makes several multi-pens. The Tri Pen works by rotating part of the barrel to chose the mode of writing. By default it includes a ballpoint, .9 mm pencil, and a highlighter. Also, the Safari line includes the Twin Pen (ballpoint and pencil) and the Twin Pen IT (ballpoint and stylus).
The Cross Matrix is a very unique multi-pen. In addition to ballpont pens and a stylus, it adds a fountain pen. I know of no other current production multi-pen that includes a fountain pen, though, back in the first half of the twentieth century, some fountain pens had a pencil on the other side of the barrel, and were called “Banker’s Pens.”
As the refill size is relatively common, different functionality can be provided in a pen. A pressurized ballpoint is available, as are alternate colors. I have replaced one of the ballpoints in my rotring 600 with a stylus. This is not meant to be an exhaustive list of multi-pens or their options, but should provide an idea of what is available.
Multi-pens are nice in that they provide a variety of tools in one instrument—you’re never really without your pencil. Further, as it can fit in device, the chance of looking like a nerd are reduced. A pocket protector full of ballpoints and pencils is not required. As both a fountain pen collector and someone in a technical field, I appreciate this, as I am probably already on that borderline.
Sources:
http://www.lamy.de
http://www.fountainpenhospital.com