This is absolutely normal: galley view does not include graphic edits, nor performs any collision avoidance. It’s really meant to enter notes and manage the different instruments (instrument changes, divisi, etc…)
Just that because Dorico treats them as staff-attached, they’ll appear differently in galley view and won’t appear in the parts of the 2nd staff downwards (they’ll only appear in the top staff’s part, I imagine).
You could also use graphics in graphics frames, but those of course are locked to the page rather than the music.
You can create new and edit existing hooks in the Edit Line Annotations dialog, including changing the hook thickness (top result when searching “hook thickness”).
Sorry David, page numbers don’t mean an awful lot as they can change very easily when the documentation is being updated regularly. I guess you mean this page? Yes it might be worth linking up that wording (which generally correlates to what the corresponding property is for individual control) to the editors a bit more clearly, I’ll make a note.
In the meantime you can also refer to the page for the Edit Line Annotations dialog that I linked earlier, which states “All types of annotations can be used as caps.”
I think the only problem (at least in terms of my understanding the concept) is that using annotations to mean both text along the line (as in the drawing) and also end caps (which are graphical elements) is not at all clear, or as expected in common use of the term.
When I go to edit the thickness of the lines used by my custom-defined line (which is based on thick), I cannot find the name of my line in the dialogue. Does this mean that all lines that use a thick vertical will be changed by my edit, or can I apply the changes only to my custom-defined line?
When playing around with lines, I always work on copies of the elements (use the +/duplicate buttons at the bottom and give your copy a meaningful name). This applies to lines, line bodies and annotations. Then I know I’m not mucking up any pre-defined line!
I have selected a similar shape line and defined a new instance with its own name. Then when I go back to /Library/Lines I can select my named line.
Then when I go to “Line Body Editor”, the confusion arises because the text in the “Name” box changes from the name of my newly-defined line to Dashed line body (long). I then have to select Solid body line (thin) – which it already was! I change the thickness of the line and ALL the solid vertical lines change thickness, even though I have not clicked default.
The reason for defining this new line is that I want it thicker than the other standard vertical lines (i.e. 1/4 rather than 1/8), which I shall still need to use for other purposes.
Can someone give me the key to changing the thickness of my line without changing all the others, please?
You need to create your own line body too (as I said) and use that one as the body of your new line type. Similarly if you want to change the thickness of the hooks, create your own hook and change that one!
(The built-in lines just assemble the built-in elements. Change the built-in elements and the built-in lines - that use those elements - will also change)