Butter is usually the fat of choice and I use both salted and unsalted, but on the whole I prefer unsalted butter for floral baking. For earlier generations, salted butter was the norm, and I never noticed any detrimental effect in my mother’s baking. As an alternative to butter, or sometimes combined with it, lard is an excellent fat for baking, especially for pastry or anything which requires crispness and lightness. Olive oil is also used in baking, and in small quantities this is manageable. I find it does alter the texture of the cake if overdone, making it heavy. I prefer to use natural fats rather than margarine.