Would somebody please explain the difference? I did a search, but all I could find is that the modified version may have corn syrup or glucose added. It doesn't say how much. Also, besides different ingredients...why would you choose modified vs. regular? Thanks for your help!

Some additions to Royal can add shine, or smooth texture, or make it thinner. There are lots of reasons to modify royal.

If you need something strong, to hold it shape, royal with fress egg white and cream of tartar is the best you can get. You might use this for flowers or stingwork.

Otherwise, it doesn't really matter.