An object's default properties are set in two places within Dia. First, as discussed above in Default Color, Line Width, and Line Style, default values for the foreground and background color; the line width; and the line style of all basic objects and some special objects are determined by settings on the Toolbox. For basic lines, the default beginning and ending arrow styles are also determined by the Toolbox settings.
The rest of an object's default properties can be set using the Defaults: Properties dialog box for each object. This is opened by double-clicking on the object's icon on the Toolbox. Since the available properties for each type of object can be different, each object's default properties dialog is different. Below are examples of the default properties dialog for the basic Text and Box objects.
For objects that include text, the dialog will normally include the text alignment, the font name, the font modifier (normal, bold, etc.), and the font size (in centimeters, not points). This makes it possible to set defaults for text display for any object that can contain text.