Margins, columns and resizing pages in Layout by Zaweba
Set margins and columns per page, use uneven column widths, and let layout adjustment and liquid rules rearrange frames when pages are resized.

Margins and columns are the skeleton of a page. They decide where text sits, how wide a line runs, and how much white space frames the content. Layout by Zaweba lets you set them page by page, and then helps rearrange things when the page size changes.
Margins and columns per page
Margins and columns can be set for each page: the number of columns, the gutter between them, and uneven widths where the columns aren't all the same.
Uneven widths open up layouts that equal columns can't. A narrow outer column for captions, pull quotes or notes beside a wider column of main text is a classic book and magazine arrangement. A report might use a slim side column for headings with the text beside it.
Because the settings are per page, a document can mix layouts. Feature pages in a magazine might use three columns while the contents page uses two uneven ones.
When the page size changes
Layout adjustment rearranges frames when the page size changes, so the content follows the new margins and columns instead of being left where it was.
Alternate layouts and liquid rules go further. When a page is resized, the rules can scale content, re-centre it, or reposition it by guides or by objects. That's the tool for adapting one design to another size, such as making a smaller version of a poster or a different format of a brochure.
Scale suits designs where everything should simply grow or shrink together. Re-centre keeps content in the middle, which works for a centred cover. Repositioning by guides or objects suits layouts where some things should stay put relative to edges while others move.
Choosing good margins
Generous margins make a page easier to read and look more considered. Tight margins pack more in but feel cramped. For books, the inside margin needs to allow for the binding so text doesn't disappear into the spine.
Column width affects reading. Very wide columns are tiring because the eye struggles to find the next line; very narrow ones break words awkwardly. Choosing the number of columns with the type size in mind keeps lines a comfortable length.
Column and resizing pitfalls
Setting columns on individual pages when they should be on the parent page means repeating the work. Put the standard layout on the parent and change only the exceptions.
Resizing pages without checking the result is another. Layout adjustment and liquid rules do a lot, but no rule can know every design intention. Go through each page after a resize and fix what needs a human eye.
Forgetting the gutter is a quieter one. A gutter that's too small makes columns run together, especially with justified text.
A good way to judge all of this is to fill a test page with real text at the size you intend to use, then look at it in Preview at actual size. Margins that looked generous on an empty page can feel tight once the text is in, and a column count that seemed elegant can produce lines that are too short to read comfortably. A few minutes of testing before the real copy arrives saves rebuilding pages later.
Good margins and columns are invisible to the reader, who simply finds the page easy to read. In Layout by Zaweba they're also what makes a resize manageable rather than a rebuild.