Dip pens generally provide more contrast than a ballpoint, and allows for variable line thickness depending on pressure and stroke. If you have never used a dip pen for any type of sketching, you should give it a try.
Although there are many types of pens like this available, I decided to design and manufacture my own around an existing nib. The design incorporates a standard available component (the nib) and the re-implementation of waste material (copper tubing) in its assembly. The nib was manufactured in England and purchased locally in South Africa from a stationary supplier. The bodies of the pens are cut from copper tubing from the refrigeration industry (presumably). The copper is then polished to luster, which also removes any edge burrs. The design is straight forward - the nib fits into the copper tube, and gets bonded in place with a suitable thermoplastic adhesive. A test prototype has been in use for several months and proves successful. The copper will tarnish, which can be brought back to luster if desired, with a suitable brass/copper polishing compound. Personally the ink and tarnished copper adds to the pen's appeal.
You can also see this design on my website at http://www.jozidesign.co.za/products_dip_pen.html