I have been doing 1/1 (one cup shortening to one pound sugar) but this new shortening I got (thought it was sweetex, but I guess not although it is hi ratio) seems to be too much in that recipe. What do you use?

I use 5 1/2 cups of hiratio shortening to 5 lbs of PS. It crusts beautifully. This is following sugarshack's recipe.

Whether I use Crisco or high ratio shortening, I use a 1 cup shortening to 1 lb powdered sugar ratio. With my recipe, I can smooth immediately with a paper towel. My recipe has to be interchangeable because while I personally use high ratio shortening, my students are instructed to use Crisco.