I am decorating gingerbread cookies for somebody long term and my cookies are lovely and crisp until I ice them, then they soften. My royal icing is just icing sugar, egg white and a pinch of cream of tartar. What am I doing wrong? I used to decorate cookies years ago but I don't remember them going soft. Help!!!

How are you storing them? I know that some cookies have to be left out, not sealed up, or they'll go soft. Other than that, I'm sorry I can't be of more help.