You can create columns within a text frame by
using the Text Frame Options dialog box.
To
create columns of unequal width or height, add threaded text frames
side-by-side on either a layout page or a master page.
Using the Selection tool, select a frame, or using
the Type tool, click inside the text frame or select text.
Choose Object > Text Frame Options.
Specify the number of columns, the width of each column,
and the spacing between each column (gutter) for the text frame.
(Optional) Select Fixed Column Width to maintain column
width when you resize the frame. If this option is selected, resizing
the frame can change the number of columns, but not their width.
Fixed column width
A.
Original 2‑column text frame
B.
Resized
with Fixed Column Width deselected (still 2 columns)
C.
Resized
with Fixed Column Width selected (4 columns)