TUBULAR TIPS FOR HAND-HELD TECHNICAL PENS USING INDIA INK ON TRACING PAPER PART 1: DEFINITIONS, DIMENSIONS, DESIGNATION AND MARKING (ISO 9175-1:1988, IDT)
This part of ISO 9175 specifies the dimensions for tubular tips for hand-held technical pens using India ink on tracing paper, irrespective of their design and manufacture, to ensure consistent line thickness within predetermined specifications, with or without lettering guides and templates.
It applies to commonly used draughting operations such as tracing, writing and lettering.