UI Image Scrolling Background fit all resolutions.

Hi,

I've saw the tutorial teaching how to make a scrolling background using a quad, but I coudn't make it fit all resolutions, so I've tried to do it with a UI Image, scalling with the screen size, but know I can't access the offset of the material.

If someone could help me, I need to scale the quad or change de Image offset (I haven't find an answer).

Thanks.