These images were created with a traditional pen and ink technique using a pen with a removable nib (the old fashioned pen you dip in ink). I typically ink on vellum (Denril). It has a nice smooth surface,and a tough pliability. This technique is one of the hardest to master and takes a while to learn, but it's one of my favorite techniques! It takes lots of patience and a steady hand! I'll sometimes use a technical pen for drawing hard edged instruments.
Disclaimer: Please note that all of these images are protected under U.S. copyright law, and the images are either owned by Madison Creative or by some other companies that were gracious enough to let me use them for the web. They may not be legally used in any way without the owner's written permission.