Which statement best describes data-ink ratio?

• A. It measures data quality
• B. It measures the speed of rendering
• C. It measures color saturation
• D. It measures the amount of ink used to present data compared to the total ink used

Answer: (D)

Data-ink ratio concerns how efficiently a chart communicates information by comparing the ink that directly represents the data to the total ink used in the visualization. A higher ratio means more of the ink is devoted to data, while less is wasted on decorative elements like heavy borders, gridlines, or backgrounds. This idea, popularized by Edward Tufte, aims to improve clarity by reducing non-data ink without losing accuracy. The statement that matches this idea precisely is that it measures the amount of ink used to present data relative to the total ink used. It’s not about data quality, rendering speed, or color saturation, which are different concerns. For example, removing unnecessary gridlines and borders while keeping the data and labels intact increases the data-ink ratio and often makes the chart easier to read.