Area charts
Lines and area are very close. They both make it easy to show trends rather than individual values. An area chart or area graph displays graphically quantitative data. It is based on the line chart. The area between axis and line are commonly emphasized with colors, textures and hatchings. Commonly one compares two or more quantities with an area chart.
Recommended for
- Making comparison of quantities
- Showing trends
Do / Don't
Use transparency to maintain a good level of readability, when the values are close to each other ; and select the data you want to highlight.
Don’t use solid colors: it reduces visibility of data values.
Support readability by using a balanced number of axis labels.
Don’t overload the chart with numerous axis labels.
Do / Don't
Limit the number of graphs displayed in order to highlight a trend and to show a correlation.
Don’t use more than 4 lines.