Is my iPad not accurate enough or is it the stylus?

Question

I made some capacitive styli with my brother, following this video on Cnet.

I tried using it with the Wacom notebook app, and the handwriting is a teensy bit too large to work as well as a real live "dead tree" notebook.

At the moment, the app feels like a wide ruled notebook, and I'd love to be able to write as much as a college ruled notebook.

Is the problem the tip of the sponge on my styli, or is it the resolution of the iPad?

What can I do to improve the accuracy, so that I can fit more handwritten text on the page?