buttercream flowersI rarely get to pipe flowers any more, but what I would always do is use about a 1/3 to 2/3 fat ratio. I think buttercream should have more butter than shortening to really taste good. So if I was going to be piping flowers on a cake (esp. in hot weather) I would just whip up some shorten. with 10x and add cold water until it was the perfect consistancy. However, if the cake was to have alot of flowers I would make do with the regular butter cream or just blend in a little more shortening because I didn't want people to be eating alot of shortening. yeck.