Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Furnishings and Equipment (hierarchy name)
4. Tools and Equipment (hierarchy name)
5. equipment
6. [equipment by process]
7. image-making equipment
8. [equipment for drafting, drawing, and writing]
9. [drafting, drawing and writing equipment by specific type]
10. pens (drawing and writing implements)
11. technical pens

Anotations

Scope note:

Pens made of a handle and a distinctive pen point consisting of two prongs or blades held one over the other by an adjustable screw that controls the size of the gap between them and thus the thickness of the ink line. A small reservoir of ink is held in the gap. Ruling pens are basic drafting implements used to inscribe lines of uniform thickness, usually guided by a straight edge, curve, or template.