Complex vector artwork

Such artwork can sometimes export at a larger file size than it would if it were converted to a bitmap. This can be true of intricate Illustrator files that contain multiple nodes and subobjects.

To see if complex vector artwork would be smaller if exported as a bitmap in SWF, choose View > Preview Export Compression, use the Export palette to create an object export setting for the object, and click the Convert Vector Objects to Bitmaps button  in the SWF Bitmap tab. If the object is smaller with this setting on, and it doesn't contain drastic scaling animation, consider leaving this setting on.