Ruling pens precede technical pens in the history of art supplies. They were used for drawing lines by hand with India ink. This was an application for drawing lines on a commercial art mechanical. Today, ruling pens and technical pens are still being used as a medium for illustrators creating pen and ink drawings. While some artist prefer one to the other, a ruling pen is easier to clean and works well when only a small amount of ink is needed. You can also get a variety of line thicknesses from one ruling pen. To do the same with technical pens, you’d need to buy a variety of sizes.
Adjust the screw on the side of the ruling pen to the desired line thickness.
Load the pen with ink by dropping a small amount of ink into the side of the pen between the two metal reeds.
Drawing a line on paper, hold the pen perpendicular to the paper surface and draw a line in a subtle stroke. A metal cork backed ruler can aid in drawing a straight line.
Continue to add ink as needed until the drawing or use is finished.
Cleaning the pen.
Remove the extra ink from the pen by drawing until the ink is drained.
Slide a scrap piece of paper through the negative space between the two reeds to remove ink.
Rinse the pen under steady water.
Dry thoroughly so the pen doesn’t rust.
While simplistic in creation, the use of a ruling pen does take some practice to gain confidence in it's use.