I have one flow which I expect to be split over two pages.
But Dorico splits the flow so that the first page is 80% full (leaving space at the bottom of page which could be/should be used) and the second page is 76% full, and so overflows onto a third page.
I don’t understand – despite much trying – why Dorico is doing these page splits.
I think that there must be some controlling variable which I’m not aware of.
?
For starters, check Layout Options—Vertical Spacing—Vertical justification, and set the second value to a lower percentage (maybe 60%). That will space out your full pages nicely.
If you want the tighter spacing that it has presently, and all to fit on two pages, your best bet would be to add frame breaks manually where desired, and toggle on their “wait for next frame break” property.
Go to Layout Options / Vertical Justification
Set both Justify values to 60%
Go to Layout Options / Ideal gaps
and set “Inter-system gap” to 4 spaces
These settings should place all the staves on two pages, this is at least what it does on my system.
BTW it is worth to work on fully understanding what the vertical justification parameters are doing because they are essential in Dorico.
Edit: Dankreider was faster 
Thanks for your replies.
The reduced inter-system gap is crucial; I hadn’t had the courage to make such a large reduction.
That does indeed give me a starting point for further work.
I suspect I’m not the only user who finds vertical spacing controls in Dorico something of a dark art.
And I do try to understand them …
Vielen Dank
We have included a page about the vertical spacing options in the manual in order to help clarify how Dorico approaches this - you can find this in English here (and forgive me if I’ve read too much into your last sign off, but also in German here). However, just playing around with the settings yourself and getting a feel for the tools available goes a long way too!
