Click the Object Library button on the main toolbar to display the Object Library.
Select different libraries from the Drop down list or use "File","Open".
All libraries should reside in the "objects" folder.
Right clicking an object allows you to change an objects default name, filename and default X/Y scale.

Adding New Objects To The Object Library Form

There are two methods for adding new objects to a library. The first way is to drag a .png, .gif, .jpg, .ico, .bmp, or .wmf file on to a blank part of the Object library form.
To rename an object, right click it and select "Rename Object" or double click the object's label. You also have the option to rename the bitmap filename, and resize the object by right-clicking it.

Another way to add new objects is by copying a bitmap to the Windows Clipboard using Edit>Copy from another Windows application. Select "Edit" and "Paste Image from Clipboard to Object Library" to add the new icon. This method usually copies the image in .bmp or .wmf format. Note .bmp files do not support background transparency. This method worked particularly well for copying .wmf icons from Powerpoint and is how the images shown to the right were collected.

Use "File","Save Object Library" to save the updated Object Library file.
 

Tip: .png, .gif, .jpg, .ico and .wmf files support a transparent background colour.
.wmf files are also a vector format so scale nicely when resized.