Reply by funfetti

Dummy cakes are usually covered in fondant that is adhered to the cake by using crisco or piping gel. You could also dampen the fondant with water so it will stick to the dummy cake. If you don’t want to use fondant, maybe you can cover the dummy cake with Royal icing – once it hardens, you can practice your piping. I’ve never done it this way, but it’s a thought…

-- DJ - Funfetticakes