What does the term data-ink ratio refer to?

• A. The proportion of ink or pixels used to present actual data versus the total amount used in the entire visualization
• B. The ratio of data to headlines
• C. The thickness of lines in a chart
• D. The amount of ink in a printer

Answer: (A)

Data-ink ratio measures how much of a visualization’s ink (or pixels) is actually used to display the data, divided by the total amount of ink used in the graphic. The idea is to maximize the data-ink and minimize the non-data ink, often called chartjunk. A clean chart that uses only the necessary elements to interpret the data—data marks, essential axes, and labels—has a high data-ink ratio. In contrast, a chart with heavy borders, gradients, shadows, and decorative elements adds non-data ink without adding data value, lowering the ratio and often reducing clarity. So, this concept is about how efficiently a graphic communicates data by prioritizing the ink that conveys data over decorative ink.