Format the Paper Size in Word 2007
To format or change paper size of a Word document, go to the Paper tab of the Page Setup Dialog box, which is on the Page Layout tab (click the lower-right arrow in the Page Setup group). The Paper tab lets you set your page size, use paper source controls, or apply these settings to specific parts of your documents.
Setting your paper size
The Paper tab includes the following options for setting your paper size:
Paper Size: Sets the paper size. The drop-down list allows you to pick from a variety of paper sizes, including Letter, Legal, and various other envelope sizes.
Width: Sets the width of the paper. This field is automatically set when you choose a Paper Size. If you change the value of this field, the Paper Size field changes to Custom Size.
Height: Sets the height of the paper. This field is also set automatically according to the Paper Size you select, and changing the height automatically changes Paper Size to Custom Size.
Using paper source controls
The Paper tab also has the following controls for telling your printer which paper to use for the pages in your document:
Paper Source — First Page: Specifies which paper tray the printer uses for the first page of your document.
Paper Source — Other Pages: Specifies which paper tray the printer uses for the second and subsequent pages of your document.
Applying your formatting changes
You can use the Apply To control to decide which parts of your document — Whole Document, This Point Forward, and This Section — are formatted with the new settings.