Designer lets you customize your working environment by setting your preferences for many aspects of Designer. Your preferences can be saved in a profile or start-up file so that they apply every time you run Designer, or you can restrict preferences to your current work session by not saving them. If you want to maintain different sets of preferences, you can define two or more profile files. Certain preferences, such as ruler units, are saved with the document so that you do not have to reset them each time you open the document.