Last reviewed 16 Sept 2026 · 7 min read
From pencil drawing to finished drawing
Drawings are generally prepared in pencil first (light construction lines), checked, and then either darkened in pencil, inked, or traced onto a medium from which copies (prints) are made. Today most drawings are prepared in CAD and plotted, but manual inking, tracing and printing processes remain part of engineering graphics syllabi.
Inking tools and materials
| Tool / material | Description |
|---|---|
| Technical (stylographic) pens | Tubular nibs giving constant line widths; ink reservoir or cartridge |
| Ruling pen | Two adjustable steel blades holding ink between them — width set by a screw (older method) |
| Compass with inking attachment | For circles and arcs |
| Drawing ink (Indian ink) | Black, waterproof, opaque, quick-drying |
| Lettering guides/stencils | Uniform inked lettering with technical pens |
| French curves and templates | Inked curves and symbols (with raised edges to prevent smudging) |
| Erasing shield | Thin metal/plastic sheet with slots to erase selected lines |
| Ink erasers, razor blade, correction fluid | Corrections |
| Pen cleaner | Cleaning nibs to prevent clogging |
Standard pen widths
ISO technical pen line widths form a series with a ratio of about √2, e.g. 0.13, 0.18, 0.25, 0.35, 0.50, 0.70, 1.00, 1.40 and 2.00 mm — matching the √2 ratio of A-series sheet sizes so that line widths remain in proportion when drawings are enlarged or reduced between sheet sizes.
Order of inking
A standard order avoids smudging and makes it easier to join straight lines tangentially to curves:
- Centre lines (and construction references to be retained).
- Small circles and arcs, then large circles and arcs (curves first — it is easier to join straight lines to curves than the reverse).
- Irregular curves (French curve work).
- Horizontal straight lines (visible outlines), from top to bottom.
- Vertical straight lines, from left to right (for right-handed drafters).
- Inclined lines.
- Hidden lines (curves first, then straight).
- Extension (projection) lines and dimension lines.
- Arrowheads and dimension figures.
- Section lines (hatching).
- Notes, titles and lettering.
- Borders and title block.
Good inking practice
- Keep pens vertical and at uniform speed; do not press hard.
- Allow ink to dry before moving instruments over lines; use instruments with raised edges.
- Keep the nib clean; never leave technical pens uncapped.
- Clean the sheet (no grease/eraser dust) before inking; work on a smooth, hard surface.
- Use consistent line widths for each line type.
- Correction: allow ink to dry, use an erasing shield with an ink eraser (or scrape gently with a blade on film), burnish the surface before re-inking.
Tracing
Tracing is copying a pencil drawing onto a translucent medium placed over it, so that the tracing can be used as a master for reproduction (light must pass through the medium in contact printing processes).
Tracing media
| Medium | Properties |
|---|---|
| Tracing paper | Thin, translucent, inexpensive; sensitive to moisture (wrinkles, dimensional changes) and tears easily; suitable for short-term use |
| Tracing cloth (linen) | Fine cotton/linen cloth coated with starch — durable, good for inking; affected by moisture (starch dissolves) |
| Polyester (drafting) film (e.g. Mylar-type) | Dimensionally stable, waterproof, very durable and tear-resistant, translucent with matte surface; accepts special pencils and ink; best for long-term masters |
| Vellum | Treated high-quality translucent paper |
Tracing procedure
- Fix the pencil drawing on the board; place the tracing medium over it, aligned and taped at corners.
- Trace in pencil or ink following the order of inking.
- Do not trace construction lines; include all required information.
- Keep hands and instruments clean; avoid moisture and fingerprints (grease resists ink).
- Check the tracing against the original before removing it.