I found that the 10-second rule works for glace. When you drag your spatula through the icing in a bowl, it should take ten seconds, not more and not less, until it settles and it\\'s flat again. If it takes longer, it\\'s too stiff and won\\'t dry smooth and if it takes shorter, it\\'s too runny and will run off the cookie. I use this consistency for outlining and flooding. I outline a few cookies, then go back to flood.