Crowquill nibs behave differently when they are inserted into a fountain pen. When you dip the nib, the ink covers the surface and fills the tube so you've got a lot of ink to work with.
When you use a crowquill in a fountain pen, you must rely on the ink to flow through the hole near the tip of the nib, and air to flow back into the pen. This is difficult in a crowquill nib because the hole is more of a narrow slit, which constricts the ready flow of ink and air, as shown below.
Our Crowquill Pump Pen compensates for the constricted slit by letting you press the pump and force more ink through the nib. Our Crowquill Fountain Pen doesn't provide the pump, so you must rely on gravity flow, and this doesn't always work the way you'd like it to.
To offset this constraint, we have experimented with expanding the size of the hole in the crowquill nib so the flow of ink and air is less constrained. The picture below shows two Hunt 102 crowquills. The top crowquill illustrates the expanded slit, while the bottom crowquill illustrates the unexpanded slit.
When you slide the modified crowquill into our pens, it looks like that shown below.
The expanded slit permits an easier flow of ink and air, which you will find helps with your drawing.
We are providing one standard and one modified crowquill nib with each Crowquill Fountain Pen so you can find out what works best for you. You can modify your own crowquill nibs if you are handy with a handheld rotary tool, such as a Dremel. We hope to offer them soon as a regular item.