UI :: artboard background vs. background ?

[thomaso]

What is in Application Preferences the difference between Background Grey Levels?
The upper works for me, the Artboard Grey seems to do nothing. 

By the way: Do the terms "Artboard" or "Canvas" only refer to "Page"/"Spread" – or do they mean something additional in AfPub?

[walt.farrell]

The "Artboard Background Grey Level" applies to documents that have Artboards. It's easiest, perhaps, to understand this in Designer, where you usually either have a Canvas, or one or more Artboards. When you have a Canvas, the "Background Grey Level" applies. When you have an Artboard (or Artboards) the "Artboard Background Grey Level" applies.

You don't usually have Artboards in Publisher, but you could have. For example, you might File > Open a .afdesign that has Artboards in Publisher. If you do that, you'll be asked if you want to convert them to Spreads.

If you convert them, the "Background Grey Level" applies. If you choose not to convert them, then the "Artboard Background Grey Level" applies.