Last time we noticed that the widow- / orphan-control doesn't exactly do what we wanted. It's rather what word is doing - and for things like letters, or texts on a poster that is haphazardly all over the place, it is fine - but not for a book. You can be the best author in the world, but you still can't predict which line will be where - or even think about adding or removing text just to please this rule ... No, there has to be a way to make this work for all stories out there. And luckily - there is.
You need to edit the Default Paragraph Style once more, setting widow and orphan control to 0, and then we will need to go through all the text once more. But before we do that - here is something else, that will make your book into a master piece.
The Main Text Block always begins on a right side - on the side you first look at, when opening a book. Every new chapter should begin on a right side, too. Scribus does support Page breaks, but it is far nicer to have each chapter in their own linked text frame. But every time we add a page, the created Text Frame is automatically linked to the one before. Now, here is the trick: You can unlink Text Frames. Click the text Frame you want to unlink, then find Item in the menu, then go to Text Frame Links and select Unlink Text Frames - or press U on the keyboard and click on the Text Frame you want to unlink. If you have added Text already, the bottom most option in the Text Frame Links menu might be for you: Unlink Text Frames and Cut Text. This will cut the text into two pieces - leaving exactly what fits in both frames. If your chapter break is in the middle of the page, you might need to move some parts manually, but it does make life a lot easier.
If you have paragraphs with four lines that fall on the page-break and create either an Orphan or a Widow, or if you have a two-line paragraph, that creates both orphan and widows, you somehow need to get rid of a line ... or expand to get another line. Without editing text. This is a lot easier on smaller pages with a relatively large font than on big pages, with a relatively small font. Real problems surface, if you have a three-line paragraph that produce orphans or widows, as you might need to do something about two lines.
Find a long paragraph - these hold the secrets we need. One where the last line is very short, is perfect for shortening by a line, those where the last line almost fits the whole space is perfect for lengthening the paragraph. Place your text-cursor somewhere in that paragraph, then go to the Text Properties Window, and expand Advanced Settings. Find Glyph Extension at the bottom. If you need the paragraph to take less space, set the Glyph Extensions Min 1 to 4% lower, if you need more space, increase the Max, or even the min. If you stay in values of ± 5%, then the effect on the Glyphs itself isn't noticeable, but it does the trick. If you need more than 5%, then try a different paragraph - but with hyphenations, the above mentioned values should be enough. There is also the option of working with Word Tracking, meaning the minimum distance between words - or the normal distance. It is important to notice that less is more. If you can get the same effect on a different paragraph with less changes, then go for that. Extreme changes will be visible.
You might notice the effect in the following screenshots - but you know the secret now.
I haven't worked with hyphenations in these. Use them. Undoing hyphenations might even give you the extra line you need. Speaking of Hyphenations. There are a few more tweaks with those you might want to consider:
Then you may specify Words that the Hyphenator should ignore, and even add exceptions, that is words that the hyphenator doesn't hyphenate correctly (add the word with dashes inserted at the correct hyphenation points).
This should give you a nice, and professional looking book-block, if you are thinking of doing a print-run of your self-published book.
