Knead the black polymer clay until it reaches a consistency similar to bread dough. On a piece of wax paper, separate the clay into two halves. With one half, form into a tube 1 inch in diameter and about 3 inches long. With the other half, form the clay into a thicker and shorter tube with a 1 1/2 inch diameter and about 2 inches long. Slightly round one tip. Attach the other tip to the first tube to become the body of the pen.
Knead the gold polymer clay until it reaches a consistency similar to bread dough. Roll a dime-sized amount of the clay into a long, thin tube. Attach this to the bottom of the body of the pen to indicate the joint where the nib enters the body of the pen. Roll a slightly thicker tube of gold clay and attach it to the joint between the two parts of the pen's body. Attach a small rectangle of gold clay to the thicker part of the pen's body just below the rounded tip to make a clip-on handle.
Mold a cone 1 inch in diameter to make the nib, using a thumb-sized amount of gold clay. Carve away a segment from one side of the cone, arcing from the tip to the base, using a toothpick. Attach this to the bottom of the pen, with the carved-out section facing the bottom and the tip facing away from the pen.
Preheat the oven to 275 degrees. Place the pen in an oven-safe dish and put it on the center rack of the oven. The general rule of thumb is to bake a polymer clay sculpture for 30 minutes for each 1/4 inch thickness. As the thickest part of the pen sculpture is roughly 1 inch thick, bake the sculpture for 2 hours.
Insert a toothpick gently on the underside of the sculpture to check if the sculpture is done. If the toothpick cannot pierce the surface, the sculpture is done. Let cool for at least 25 minutes before handling.
Draw a thin line in permanent ink down the top of the nib. This will suggest the line in the nib through which ink flows. For presentation, write a note on a piece of paper in black ink and place the pen model on the paper.