Hi Brian,

> I see that there is an option to "Embed image data in 3dm file," so the images do not
> need to be in the final 3dm file?

Yeah it's optional for whether the 3DM file will contain the actual image bits embedded inside of it or not, by default when you create a background image it will only reference a file on your disk. If you turn on that embed option for an image it will include the image bits inside the 3DM file which can be convenient for sending the file to other people since everything is contained in just one file.

- Michael