Ballpoint Twist Pens With Cross-Style Refills
You extend the refill by twisting the top half of these pens. All of these ballpoint pens take Cross-style refills, available at most office supply stores.
Cross-style ballpoint refills are thinner than Parker-style which is why these thinner diameter pens utilize them. I find less difference among brands in these refills than with the Parker-style. My favorite is still the Private Reserve brand from Germany. These write smoothly with no skipping. The Monteverde Broad Point is also a nice writing refill and Cross makes a "Broad Point" refill that writes smoothly and leaves a wider darker line that many like.
Typical measurements: Length 5.2", Diam 0.37", Wt 0.7 oz
As the name implies, this is the thinnest of the pens and a relatively classic style. Some really like the thin design, while others prefer to hold something a tad thicker when writing.
Typical measurements: Length 5.1", Diam 0.46", Wt 0.9 oz
This is a slightly thicker version of the Slimline. There is a rubberized cushion option available that goes just above the nib if you prefer a cushioned grip, hence the name Comfort Pen.
Typical measurements: Length 5.3", Max Diam 0.48", Wt 1.3 oz
This pen is made from a genuine shell casing . A copper bullet was drilled out to form the nib. The clip and top finial are identical the Slimline.
European Twist Pen
Typical measurements: Length 5.1", Max Diam 0.54", Wt 1 oz
This is the classic European style pen with the wider upper body and narrower lower body. The domed top is a signature of the European style pen