1, page setting, paper type selection, custom size specification: width 29.7 cm, height 42 cm.

2. Page setting paper selection and selection A3.

3. Set the column spacing: the format columns have the same width. In general, page setting: margin 2 1.7, column width 2 words printing: (printing on A4 paper requires scaling) File printing is scaled according to paper size. Select A4 and confirm the page number: just operate in the left column footer.

The above is how to add the cover of paper a3 to a4.