The Scalable property is set to True by default. When the Scalable property is enabled you can use the ScaleEffects property to set the scale factor for the image. You can set the scale effect factor from 0 to 1. The default value is 0.5. Given a scaling factor greater than 0.5, scaling will brighten the image and less than 0.5, scaling will darken the image.

You can achieve a more brightening or darkening effect using the ScaleEffects property more than using the Offset property since it preserves the relative contrast of the image better. You will not notice the effects of the ScaleEffects property if the Offset property is zero.

You can specify the width of the element's edge by setting its Width property. When the Scalable property is true it is measured in relative units, otherwise it's measured in pixels.

For more information on applying scaling and edge effects to a chart element, see Increase the Size of the Symbols in the Data Series.