To create a double page (full-spread) master, you have to readjust the column widths, as by default on the double page, they refer to a fake spread.

Create a new full-spread master

1.Right-click a default double-master and then click Duplicate.

2.Enter an appropriate name for the new full-spread master, and then click OK.

3.Open the new full-spread master, and then design a temporary single frame from the left outer margin to the right outer margin,

4.Press the S key to split the frame in the default number of columns. Please note that the central columns enter in the inner margins.

5.On the Layout menu, click Remove all guides.

6.On the Layout menu, click Add object guides. This will add the column guides, aligned to the temporary frames.

7.On the Layout menu, click Set baseline grid (Modules and Nudge), select the values and then click OK. This will add the module guides.

8.Delete the temporary frames and then save the master page.