World's Most Sold Fountain Pen One of the most useful fountain pens ever produced is the Parker 21. It's hard to break, never leaks, and always functions. The Parker 21 pen was the first to have its nib protected by a hood. This design decision was made to prevent ink from drying out while it was being transferred from the ink reservoir to the paper. Parker 21's body was made to resemble a jet fighter from the side, and its nose was made of the same Lucite material as some wartime aircraft. cones Parker 21 Lacquered & Scratch Resistant Grey, Stainless Steel Fine Nib & Brushed Steel Cap with Shiny Chrome Trim Included Parker Squeeze Converter for Ink Combine with a bottle of Parker Quink Ink. Parker's Collector's Top Pick