A ruling pen is a vintage drawing instrument for drawing with ink or with other drawing fluids.

A ruling pen contains ink in a slot between two flexible metal jaws, which are tapered to a point. It enables precise rendering of the thinnest lines. The line width can be adjusted by an adjustment screw connecting the jaws. The adjustment screw can optionally have a number dial.

Originally used for technical drawings in engineering and cartography together with straight rulers and with french rulers, it is today used for specific uses, such as picture framing

Picture frame

A picture frame is a decorative edging for a picture, such as a painting or photograph, intended to enhance it, make it easier to display, or protect it.-Construction:...

 or calligraphy

Calligraphy

Calligraphy is a type of visual art. It is often called the art of fancy lettering . A contemporary definition of calligraphic practice is "the art of giving form to signs in an expressive, harmonious and skillful manner"...

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