Step 1: Create a standard text (transaction SO10) and insert the background image in it

Step 2: Now open the layout set (transaction SE71) in which background image needs to be displayed and do the required changes as mentioned below.

Note: Here I am using an existing custom sapscript layout where all windows, pages and page windows are already created except the background image. And for this demo I am showing the changes required for inserting the background image in the 1st page.

Now in the 2^nd line insert the special command NEW-WINDOW

Definition of NEW-WINDOW command:

Each page can consist of up to 99 main windows. Each main window is assigned a consecutive identifying number (0..98), and the windows are filled in this order. This feature enables SAPscript to print labels and to output multi-column text. When one main window fills up, the next main window on that page is taken, if there is a next one. A page break is inserted after the last main window.

You can use the NEW-WINDOW command to call the next main window explicitly, even if the current main window is not yet full. If you are in the last main window of the page, the command has the same effect as the NEW-PAGE command

Now activate the form

Step 3: Maintain required configuration for triggering the form

Step 4: Now trigger the form and see the print preview

Result:

Form is displayed with background image in print preview.