Hi! I'm trying to construct a cake for a decorating contest and I'm wondering if I should use canned frosting. No one will eat the cake so I'm thinking it's a  cheaper alternative to buttercream. BUT since it'll be on display for many weeks I worry that it might lose its shape or melt. Has anyone tried anything like this? any tips would be greatly appreciated. 

Yes it can be used   It might get soft from the heat in your hands making it difficult to work with   It will dry out rather than melt — unless it’ s very humid— never used it in real humid areas    Just remember the more you stir it the softer it gets:(  it can be thickened by adding cornstarch, flour,  or powdered sugar 

Also, if you want it to crust, heat it in the microwave and then chill before using.  For some reason the heating causes it to crust really well.