Impress - Background settings for all pages?

I was used to work with LO5. For setting the background-image of all slides, I used the following sequence :
Slide → Set Background Image…

After selecting the image, a menu popped up with the question “Background settings for all pages?”

With LO6 this menu no longer pops up. How can I set a background-image for all slides in LO6?

Setting something “for all” slides means, that it is a setting of the master slide. So click on ‘Master View’ in the property deck of the sidebar or use menu View > Master Slide to switch to master view. Then you can set the background via Slide > Set Background Image or via Slide > Properties, tab Background. When your have finished settings, click on ‘Close Master View’ or use menu View > Normal.

Thank you for quick response. It notice that the new behaviour is not quite the same as the older one. In LO5 if you specified a background-image for a slide, the background was overwritten by the setting “Background settings for all pages?”. When one modifies the background-image in the master-slide in LO6, the slides where one has altered the background-image by “Slide->SetBackground” remain unaltered. In fact this is a behaviour I like.

If you start a fresh presentation and you start by setting the background via “Slide->SetBackground” and afterwards you change the background of the master-slide, then the first slide will still have the first background entered. The same applies if you have duplicated the first slide. One can revert to the new master-slide-background by specifying “no background” in the property-deck. This is a little bit counter-intuitive if you were used to work LO5.