Parker 61 capillary filler

Corrugated and/or perforated rolled material is inside what would otherwise be the cartridge or converter. It is covered with Teflon that prevents ink from adhering to the outside. Simply drop the reservoir end in the ink bottle and capillary action will fill up the in reservoir in a minute or two.

Vintage ad showing how to use the pen.. Putting your thumb on your chin is optional.