Sheaffer's name for their non-lifetime nibs and later, a line of pen models.

A metal clasp attached to a pen cap to keep it firmly in place in a pocket or pen case. They often carry some part of the company logo.

The cut, through tip and nib up to the venthole of the nib - the ink is drawn through this slit onwards to the tip, from where is is drawn onto the paper, upon contact with the paper surface.

Most pen cracks are found around cap lips and come from caps being posted (placed on barrel end) too firmly. They are especially common in red hard rubber which becomes quite brittle with age. However, cracks can occur in other locations on a pen as well as in metal parts including nibs.

An Eversharp model during WW 2 that attempted to compete with the Parker 51 having a hooded nib and a metal slip cap. The pen was not successful and was only made a few years.

Generally refers to any cutout metal work in a pen's decorative metal overlay. Parker and Waterman produced many filigree pens in the early part of the century.

An unusual looking pen from Moore introduced in 1946. The pen featured an inlaid nib. It was made in several sizes and while not successful at the time, they are very collectible today and are one of the better writing pens of the era.

How easily the tines of a nib give and spread under pressure. Stiff nibs are called manifold nibs and are preferred for writing through multiple copies. Flexible nibs can produce a variable line width, and while not common since the '30s in the US, they are making a popularity comeback. In fact, some buyers are led to believe that the more flex the better, which is not necessarily true.

Beginning with an aerometric 51 in 1950, Parker began a series of all stainless steel pens called flighters. Although George S. Parker had died years before, he was a great aviation fan and the company had always been associated with aviation motifs. Flighter in the 61, 45 and 75 lines followed.

A threaded cap on the barrel end to cover a filling mechanism. Most common are Parker's Duofold which covers a button-filling device, and Parker's Vacumatic and vacumatic-filling 51s which cover pump plungers.

Hole in the nib which allows air to displace ink in the bladder or barrel. Also could be on the feed instead of the nib.

The original name of Parker's aerometric filling system for the 51. It was introduced as foto-fill in its first year, '49, then changed to aerometric in 1950.

Parker's arrow logo first appeared on the clip of the Golden Arrow, the forerunner of the Vacumatic. The arrow was used on most subsequent Parker clips and also on nibs and other parts.

The barrel describes the body of the pen which holds the ink or the ink reservoirs like cartridges or ink sacs.