A bulb filler style vintage fountain pen is a simple concept. Basically, you make the entire pen into a large eyedropper with a nib on the tip. The rubber bulb is covered by a blind cap to prevent accidental pressure and ink discharge. To further enhance filling capacity, these should have breather tubes to allow more air to be expelled with each squeeze and allow for more complete filling of the barrel reservoir. Commonly seen versions of this pen are the Postal Reservoir Pen (pictured) and Eversharp Bantam pens,
