Concept
1. What is chartjunk?
Anything that uses ink but adds no information: heavy gridlines, borders, 3-D, shadows, gradients, background pictures, legends for a single series, redundant axis titles, decimal places nobody needs.
2. The 8-step clean-up
- Delete chart border, background fill, 3-D and shadows.
- Gridlines: delete, or make them very light grey.
- Legend: delete for one series; for few series, label the lines/bars directly (data label on the last point → Series Name).
- Data labels on bars instead of an axis, when there are few bars (then delete the value axis).
- Number format: show big values in ₹ lakh or crore with 0–1 decimals. Excel's comma scaling (
#,##0,and#,##0,,) divides only by thousand/million, so for lakh/crore use a helper column (=B2/100000) and label the unit in the subtitle. - Colour: grey for everything, one highlight colour for the point of the message.
- Title = the conclusion (Lesson 1), subtitle for units and period.
- Sort and remove unnecessary categories (group the tail into "Others").
3. Axis truncation — the big ethics question
Bar and column charts must start at zero. Their meaning is length; cutting the axis lies about length.
Example (FY2025-26 revenue): North ₹9.43 cr, West ₹7.48 cr — North is about 1.26× West. If the axis starts at ₹7 cr, the bars are 2.43 and 0.48 tall — North looks 5× bigger. Same data, false story.
Line charts may start above zero when the point is the change, not the size (e.g. a share price, a temperature) — but the axis must be clearly labelled, and you shouldn't pick bounds to exaggerate.
4. Other ways charts mislead
| Trick | Honest alternative |
|---|---|
| Truncated bar axis | start at 0 |
| Two y-axes with chosen bounds | same axis for same units; label both (Lesson 3) |
| Cherry-picked time window ("last 3 months") | show a full year, or explain the choice |
| Cumulative chart to hide a recent decline | show monthly values too |
| Unequal time gaps on the x-axis as if equal | use a date axis |
| 3-D pie (front slice looks bigger) | flat bar chart |
| Percent change on tiny bases ("+300%!" from 1 to 4) | show the actual numbers too |
| Comparing a partial month with full months | complete periods only, or MTD vs MTD |
5. Accessibility
- Don't rely on red/green alone — add ▲▼ or labels.
- Font size readable when projected (axis labels ≥ 10 pt).
- Add alt text (right-click chart → Edit Alt Text) for reports shared as documents.
6. A final checklist
- Message in the title
- Right chart family for the question
- Bars start at zero; dual axes justified and labelled
- Sorted; tail grouped
- Direct labels, minimal gridlines, no legend if not needed
- One highlight colour
- Source and period in a subtitle or footnote
Common mistakes
Keeping Excel's default style "because it's standard". Starting bar axes at a convenient number. Highlighting everything (then nothing stands out).