Various/Multiple backgrounds (e.g. for site plan and grid)

[andife]

I currently have the drawing part with property boundaries as a background. Now I would like to continue working with an additional grid so that, for example, a printed centimeter corresponds to a certain length. I thought the solution could be to show a second background with a grid, for example.

Or how could other ideas be to get the basic boundary plan and a grid into a pdf or a Din A4 at the same time?