Graphics in a Calc document are maintained in a similar manner to a deck of cards. As you add more images to the document, each image occupies a new layer at the top of the stack. To arrange graphics, you tell Calc to change the order of layers in the stack.
Calc provides four basic options to re-arrange the order of images. These options can be accessed from both the Picture toolbar and the picture context menu. These are illustrated below, accessed from the picture context menu.
To Background and To Foreground
An image or a drawing object can be sent to the background as well. This is not the same as Bring Forward and Send Backward, which set the order of a number of overlapping graphics. This feature pushes a graphic to the back of the spreadsheet, behind the cells, allowing cells to be edited without affecting the graphic.
A graphic in the background will have To Foreground as a menu item, instead of To Background.