Add new textures to color boxes??

[Davinner]

Hello to everybody,
I often need to fill the text boxes or shapes (polygons, hand-made regions made by lines...) with some textures or effects. The predefined effects provided by PP (I mean when you click on "Filling" and then you choose the pads "texture"... I hope the names are so, I translate from Italian!)
are good but sometimes poors: "paper", "wood", "droplets".... I would like to add textures as for example "metal", "window", "fire", taken for example from internet images.

Does someone know how to do?
I searched in Italian sites and forum but this was not mentioned...



Thank you very much and best wishes