I am programmatically adding points to a point series of a TChart. I want to be able to change the size of the points at run time so that if I zoom in too much I can still see them. It seems it is the density of points that makes them easy to see with the chart zoomed out. When I zoom in so much that only a few points are showing, they become impossible to see. They are a good size to see well until I zoom in too much. I was thinking of adding a spin button to allow manual resizing of the points when necessary. I think, but am not sure, that what I need to change is the width and height under "Small Dot" in the format tab of chart1.series1. I don't know how to do it programmatically. Something like TChart1.Series1.Format.width := ?