What inspired this wish list request? Changing marker size/line thickness in graphs is a frequent task for me, but it takes too many clicks. I shared this idea with John Sall before, and he liked it.
What is the improvement you would like to see? Please program rotating the mouse wheel up/down while holding Alt key as a quick way to increase/decrease the marker size in any graph. For line thickness change you might want to program mouse wheel rotation while holding Ctrl key. Once a lower/upper limit is reached, further rotation of the mouse wheel does nothing.
Why is this idea important?
It increases productivity in tuning the graphs appearance to the user's needs. The idea follows the spirit and example set by on-the-fly font size change by Ctrl-Shift-+/- key combination already existing in JMP.