How can I set the default papersize to DIN/ISO A4?

Mac OS 9

In the Finder select the Page Setup command in the File menu. Select A4 paper size and then hold down the option key while clicking on the OK button. You will be prompted with an alert box asking whether you want to save the current settings as the default settings. Click Save and you are done.

Mac OS X 10.0 and 10.1

Please upgrade to at least version 10.2.

Mac OS X 10.2 and 10.3

The default paper size is set in the Preferences dialog box of the Print Center application. This application is found in the Utilities folder in the Application folder of a standard Mac OS X setup. Start up the application and access the Preferences… command in the Print Center menu. Select your paper size accordingly.

There are some applications that do not use these default values. Instead, these applications generally allow you to save your own default values in the Page Setup dialog box that appears for that application.

Note that changing the default paper size will probably not affect documents you have already created.

Mac OS X 10.4 Tiger and later

Open System Preferences… from the Apple Menu and click on Printers and Scanners. Choose the default paper size from the drop-down menu in the lower right of the preferences panel.