漏斗图把值编码为连续阶段的宽度或面积。20 世纪中叶销售管理用语；后来成为 CRM 仪表盘。
工作报告、广告与作业中适合有序流失：线索、结账、申请。若阶段并非同一总体的嵌套子集，换一种形式。
Rules
- 规则 1 — Use 连续阶段的宽度或面积 as one channel, not two.
- 规则 2 — Direct labels beat a distant legend.
- 规则 3 — Do not hide zero. If you break the axis, say so.
- 规则 4 — Colour encodes category or magnitude, not both.
- 规则 5 — Put the claim in the title, not just “漏斗图”.
- 规则 6 — Source and period, even in small type.
Palette
- 色板 1 — Categories: distinct hues. Sequences: one hue, changing value.
- 色板 2 — Diverging: a neutral centre, emphasis at both ends.
- 色板 3 — One brand colour plus greys beats a rainbow.
- 色板 4 — Check contrast on a projector and in greyscale print.
Type
- 文字 1 — Tabular figures for numbers. Do not pour body copy into the chart.
- 文字 2 — Titles as sentences; axes as short nouns.
- 文字 3 — For CJK, drop weight one step and leave tracking.
漏斗图: honour 连续阶段的宽度或面积, and switch when 阶段并非同一总体的嵌套子集.