Amogh N P
✦ In loving memory of Amogh N P — Architect · Designer · Visionary ✦
An Indian student drafting at a board fitted with a mini-drafter.
Lesson I25ARS123 · Architectural Graphics I

Setting Up the Board

Instruments, lines, lettering and scales — the standards before the drawing.

≈ 35 min

Technical drawing is a precise language, and like any language it has a grammar — the instruments, the sheet, the line conventions, the lettering and the scales. Get the grammar right and anyone, anywhere, can read your drawing exactly. This first lesson sets it up.

Learning objectives

By the end of this lesson, you will be able to — mapped to the course outcomes for Building Materials & Construction I:

1
CO1 · Understand

Identify the drafting instruments and what each is for.

2
CO1 · Apply

Lay out a sheet to IS 10711 — border, filing margin and title block.

3
CO1 · Apply

Use the conventional line types and single-stroke lettering correctly.

4
CO1 · Apply

Construct and read plain and diagonal scales; state the RF.

Kit, sheet, lines, lettering

Set up to standard

This is the instrument side of drawing — the precise counterpart to the freehand Design Drawing kit. Select a topic.

The kit

T-square or mini-drafter (parallel-arm drafting machine) for straight lines and angles; 45° and 30°-60° set squares; compass and divider; French curves; and pencil grades — 2H-4H for light construction lines, H/HB for linework and lettering, 2B-4B for bold work.[8]

Lay out the sheet (IS 10711) wide filing margin (20 mm) title block (bottom-right) trimmed edge · border · drawing space A0=1 m², ratio 1:√2 — halve any A-sheet and you get the next size down. Title block always bottom-right, read with the sheet.
DiagramA drawing sheet with border, wide filing margin and a title block in the bottom-right (IS 10711)
The language of lines (IS 10714 / SP 46) Continuous thick — visible edges Continuous thin — dimensions, hatching Dashed thin — hidden edges Long-dash dotted — centre lines, axes Chain, thick at ends — cutting plane Thin with zig-zag — break line Two weights do most of the work — a thick visible outline and a thin line for everything that supports it (roughly 2 : 1).
DiagramThe conventional line types in technical drawing and their uses
Reading and declaring

Scales & which projection

A drawing is useless without a scale, and ambiguous without declaring its projection system. The Representative Fraction fixes the first; the truncated-cone symbol fixes the second.[6, 7]

Reading more from a scale Plain scale — two units 012 mdecimetres Diagonal scale — three units (similar triangles) The diagonals interpolate a third sub-division — so you can step off two decimal places. RF = drawing length ÷ real length. A plain scale reads two units; a diagonal scale adds a third by similar triangles.
DiagramA plain scale reading two units compared with a diagonal scale reading three by similar triangles
Which projection? Read the symbol First-angle — India / Europe cone's narrow end points AWAY from the circle Third-angle — USA cone's narrow end points TOWARD the circle India follows FIRST-angle (mandated by SP 46). The symbol in the title block declares which system the sheet uses.
DiagramThe first-angle and third-angle projection symbols compared — India uses first-angle
A flatlay of drafting instruments — compass, set squares, scale, pencils.
PhotoA flatlay of drafting instruments — compass, set squares, scale, pencils.
A drawing sheet corner — inked border and a ruled title block.
PhotoA drawing sheet corner — inked border and a ruled title block.
Drafting pencils of different grades with a sharpener and eraser.
PhotoDrafting pencils of different grades with a sharpener and eraser.
An Indian student drafting at a board fitted with a mini-drafter.
PhotoAn Indian student drafting at a board fitted with a mini-drafter.
Check your understanding

Self-assessment

1. An A0 sheet has an area of:

2. The cutting-plane line is drawn as:

3. India draws in which projection system?

In a nutshell

Recap

Know the kit — instruments and pencil grades — and lay the sheet out to IS 10711 (title block bottom-right).
Use two line weights and the conventional line types (IS 10714 / SP 46); letter single-stroke (IS 9609).
RF = drawing ÷ real. Plain scale → two units; diagonal → three; vernier → finer.
India draws in first-angle projection — declared by the truncated-cone symbol.
The standards

References & further reading

  1. [1]ISO 216 — A-series paper sizes (A0 = 1 m², ratio 1:√2). Overview. https://en.wikipedia.org/wiki/ISO_216
  2. [2]IS 10711:2001 — Technical product documentation: sizes and layout of drawing sheets (= ISO 5457:1999). BIS. https://law.resource.org/pub/in/bis/S01/is.10711.2001.pdf
  3. [3]IS 10714 (Parts) / ISO 128 — General principles of presentation: line types. SP 46:2003 consolidates for schools. https://law.resource.org/pub/in/bis/S01/is.10714.30.2006.pdf
  4. [4]IS 9609 / ISO 3098 — Technical product documentation: lettering (single-stroke Type A/B; standard heights). https://law.resource.org/pub/in/bis/S01/is.9609.1.2006.pdf
  5. [5]IS 11669:1986 — General principles of dimensioning on technical drawings (= ISO 129:1985). https://law.resource.org/pub/in/bis/S01/is.11669.1986.pdf
  6. [6]ISO 5455:1979 — Technical drawings: scales; plus the plain/diagonal/vernier scale constructions. https://www.iso.org/standard/11500.html
  7. [7]SP 46:2003 — Engineering Drawing Practice for Schools and Colleges (BIS); India uses first-angle. https://law.resource.org/pub/in/bis/S01/is.sp.46.2003.pdf
  8. [8]Drafting instruments and pencil grades — standard drafting practice (consolidated in SP 46). https://en.wikipedia.org/wiki/Technical_drawing_tool

Further reading

  • Ching, F.D.K. (2023). Architectural Graphics (7th ed.). Hoboken, NJ: Wiley. ISBN 978-1-394-20626-1.
  • Bhatt, N.D. (2014). Engineering Drawing — Plane and Solid Geometry (53rd ed.). Anand: Charotar. ISBN 978-93-80358-96-3.
  • Bureau of Indian Standards (2003). SP 46: Engineering Drawing Practice for Schools and Colleges.

Sources gathered and fact-checked June 2026. Published values vary by source, sample and method — treat as indicative and confirm against the cited standard before structural use.

Design Drawing courseThe freehand companion — sketching, observation and perspective by eye.