How to make
Sift the powdered sugar through a sieve and transfer it into a bowl. Add the vanilla, egg white and starch to it.
Beat with a mixer on low speed for 3 - 4 minutes, then add the lemon juice to the mixture and beat briefly again.
Cover the icing with a damp cloth for about half an hour to melt any remaining sugar crystals.
Then, using a teaspoon, add cold (ice) water a little at a time, until the desired icing consistency is obtained, by mixing with a spatula, not a mixer. The amount of water can vary from a few teaspoons to a few tablespoons depending on the thickness you want to achieve.
If desired, you can add confectionery paint in the color of your choice.
After applying the icing, they should be left at room temperature for a few hours, until the icing dries completely.
You can store the unused royal icing in a tightly sealed bag in the refrigerator.