Royal Icing is an icing that becomes hard when air dried. You can make flowers or other things as I have done here. These are the letter "A" that went on top of a bridal shower cake, for individual servings.
4 cups confectioners' sugar
3 tablespoons meringue powder
1/2 teaspoon extract vanilla, lemon, or almond
1/2 - 3/4 cup warm water
With a mixer beat the confectioners' sugar and meringue powder until combined.
Beat in water on medium to high speed until very glossy and stiff peaks form 5 to 7 minutes.
You can add paste coloring to add color.
Keep the bowl covered with a damp towel. It dries out very quickly.
Fill your pastry bag and use a small round tip for piping, or a flower tip to make flowers. Keep your bag covered with a damp cloth so it will not dry out.
Pipe out what you need onto wax paper. Let air dry for a few hours.
To lift, slide a knife under the "A's", this will help keep them from breaking. Always make double of what you need to allow for breakage. These can be stored in an airtight container for several months.
This is a sheet cake, each serving has an A with a leaf on it.