Remove border of detail view

This ‘problem’ has suddenly arisen… I think I must have changed an option somewhere
All detail views are now displaying a ‘border’ which I can’t stop from printing (I don’t want a border around my views… or if i do i just draw a rectangle.
Can anyone point me in the right direction ?
Have tried changing properties of the detail view… but it doesn’t change anything

edit : it’s ok set to ‘no print’ for some reason changing the colour (alone) wasn’t working