I have so much left over...

if I use it to pipe a cookie, will it get as hard as royal?
Can I add anything to make it hard as royal?
How long can it be stored and best way to store (room temp, freeze, fridge?)

I keep hearing about this icing...where can I find the recipe?

It will get very firm, dry enough to pack, but not quite as hard to eat as royal.

To Schmoop- on the home page you will find a link to the "bake and decorate a cookie" instructions. the recipe and instructions are there.

Thanks! I have never been satisfied with the icings I use, I will certainly try this!

It IS royal icing...just thinned.

It gets hard enough to pack, but I let cookies dry 24-36 hours before I package them.