ISO 9957-2:2019

Overview

ISO 9957-2:2019 - "Fluid draughting media - Part 2: Water-based non-India ink - Requirements and test conditions" specifies quality and test methods for water-based non-India inks used in draughting instruments on natural tracing paper (ISO 9961). The standard defines performance criteria and test conditions to deliver consistent black-line technical drawings while noting that non-India inks are generally less fade- and reproduction-resistant than India ink and are not recommended for archival originals.

Key topics and technical requirements

• Scope and purpose: Requirements for black water-based draughting fluids that do not use carbon black as primary colourant (dyes, dispersions, microfine pigments).
• Test atmosphere: Tests are carried out under standard test atmosphere 23/50 (ISO 554).
• Test specimens and equipment:
  • Natural tracing paper conforming to ISO 9961.
  • Electromechanical line-drawing device (adjustable angle, load, speed, pitch).
  • Tubular technical pen, densitometer (ISO 5-2 / ISO 5-4), profile projector or measuring microscope, xenon lamp for fade testing.
• Measured properties:
  • Line width - measured microscopically or by projection; averaged from multiple measurements and compared with allowable deviations (see standard).
  • Optical density - transmission or reflection density measured with a densitometer; an optical density of around 1.0 is indicated as adequate contrast for many reproduction processes.
  • Drying time - defined procedure (finger-glove smear test) to verify rapid set.
  • Adhesion - tape test and eraser/lead abrasion tests to check durability of line intensity.
  • Erasability / redraughtability - specified erase and redraw test; acceptable behaviour must be recorded in test report.
  • Resistance to water - controlled water-drop test; limited spreading allowed but no loss of line intensity.
  • Fade resistance - light fastness assessed with a filtered xenon lamp; non-India inks are explicitly not archival-grade.
• Shelf life: Graphical and mechanical qualities must be preservable for at least two years under supplier-recommended storage conditions.

Applications and users

ISO 9957-2:2019 is relevant for:

• Ink manufacturers developing water-based draughting inks and cartridges.
• Technical pen and instrument manufacturers specifying ink compatibility and performance.
• Quality control and testing laboratories conducting standardized performance tests.
• Drafting and CAD departments that still produce hard-copy technical drawings on tracing paper. Note: Users needing archival permanence or guaranteed reproduction by traditional photomechanical methods should consider India inks or alternative archival processes.

Related standards

• ISO 9961 - Natural tracing paper
• ISO 5-2 / ISO 5-4 - Density measurements (transmission/reflection)
• ISO 2240 - Photography (ISO speed)
• ISO 9177-2 - Mechanical pencil leads
• ISO 10209 - Technical product documentation - Vocabulary

Keywords: ISO 9957-2:2019, water-based non-India ink, draughting inks, tracing paper, line width, optical density, drying time, adhesion, erasability, resistance to water, technical drawings.