Professional Detailing2 min read

Logarithmic Charts in Coating Reports: Label the Scale and Interpret Ratios

A logarithmic axis represents proportional changes differently from a linear axis. Label it clearly so readers do not interpret equal visual distances as equal absolute differences in a coating comparison.

Updated · NANOLAB Knowledge

The key distinction

A log scale can be useful when values span a broad range, but the reason for using it should be apparent. Keep units and tick labels visible. Values that cannot be represented on the chosen scale require an explicit treatment rather than silent removal from the chart.

Practical checks

  1. State the scale type and preserve readable tick values.
  2. Explain the comparison the chart is intended to show.
  3. Disclose omitted or transformed observations and retain the original data.

Example

Arithmetic example: on a base-ten logarithmic axis, the distance from 1 to 10 equals the distance from 10 to 100. Both represent a tenfold increase, although the absolute changes differ. A reader needs that context before judging the visual size of a coating result's change.

Scope and limits

Do not select a scale to exaggerate or conceal a preferred result. This guide does not recommend a transformation for every dataset. The analyst should choose a display suited to the question and make the representation clear enough for a non-specialist buyer to interpret accurately.

Related guidance

Ask NANOLAB about the exact product and intended use. Use the current product documentation for formulation-specific instructions.