AI love baking to the point where it's a problem, particularly cake making and decorating, and I finally decided to order styrofoam cake dummies online so I can practice decorating without us eating fifty servings of cake every night. I'm not really sure what to do about the frosting, though. It has to either be really really cheap or something I can reuse and preferably both, and taste doesn't matter at all. I know you could make a frosting that would keep for a long time with powdered sugar, water and shortening but I don't want it to crust because I'd like to be able to scrape it off and store it to use again.

ACrusting is a function of the fat to sugar ratio, nothing else. My recipe uses 1 pound of fat to 1 pound of sugar.there's not much crusting.

Areally? Because I always make all butter buttercream because it tastes better and doesn't leave a waxy feel in your mouth and that barely crusts even though the sugar is way higher than the fast.

AThe link isn't working, possibly because I'm on ipad. Can somebody just write it out?

Anvm I figured it out but his has butter which doesn't crust as much, but it would go bad unless I did all shortening which I'm worried might crust. :-(

1 cup of fat (butter or shortening) to 1 lb (4 cups) of powder sugar and 2 TBS liquid is a crusting buttercream.  As stated before, it is all about the ratio of fat to sugar. the more fat, the less crust you will get. the less fat you have, the more crust you will have, to the point of it being crumbly. The balance is finding the right ratio.  It also depends on your local humidity. A dry, arid envrionment is going to have a different effect on a cake than a humid rainy one. 

AIf anyone ever has the same question here's what I did: I used the recipe that fits in a stand mixer on www.cakesuppliesplus.com with an extra pound of shortening. I replaced about a third of the water with clear corn syrup and didn't use any flavourings since it's for practice. I don't know if it was the corn syrup or extra fat but it was a great consistency and it didn't crust at all.