Transparent render background (Noob!)

in New Users
Hi there!
I used to play around a little with Daz a couple of years ago and now I want to try it again.
My question: when I rendered my images the background was always black, but now it's transparent
(i.e. the grey and white squares). How do I change that back? To clarify: I want all my untextured
surfaces to be black and not transparent. (And I don't want to use another software if possible.)
Thanks for reading!
Comments
Window-Panes-Environment. Set the Backdrop color or image from there.
Thank you!
Is there a way to set the background option as the standard setting?
Simply saving as a format that doesn't support alpha channels/transparency will remove the transparency from a saved image (the chequer board pattern in the render window is just telling you where transparency will be, it isn't saved as such).
OK. Thank you both very much!