Keeping graphics unaltered when TabPage changes

I have a form that displays a set of graphics using a Paint event on a Panel that is docked inside a particular TabPage of a TabControl.

The problem is the following:

When the user switches to a different TabPage and then decides to go back to the TabPage where the graphics were originally displayed, those graphics are invalidated by default so the Panel appears blank.

I would like those graphics to stay unaltered and totally independent from the user's action when switching between different TabPages.

One Requirement:

Since the graphics are complex and take some time to be drawn by the computer, I don't want to repaint the graphics each time by calling the Paint event repeatedly. Instead, I only need to avoid the default invalidation of the graphics.

I have read this other question which may be helpful to solve my problem but it goes beyond my knowledge.