To access the format painter in most applications, you need to press Ctrl+Shift+C. This keyboard shortcut allows you to copy the formatting of a selected object or text and apply it to another object or text. By pressing Ctrl+Shift+C, you activate the format painter tool, which then allows you to click on the target object or highlight the target text to apply the copied formatting. This shortcut is commonly used in programs like Microsoft Word, Excel, and PowerPoint to quickly apply consistent formatting throughout a document.