Does anyone know where I can find white margarine to make buttercream frosting?[/b]

I use Land O Lakes unsalted butter... It pretty much comes out white... You can always add Wilton's White Out to make it bright white... Hope that helps!

I prefer butter myself. Another tip on getting white icing is use a little bit (I mean a little bit like a toothpick tip full) of violet gel coloring. Add it to your finished BC and mix. It counteracts with the yellow turning your BC white. I do this all the time with my cakes - all the white cakes in my photos have been made doing this.

Why in the world are you using margarine in the first place?????

Where are you located and what recipe are you using ??

Yeah, I wouldn't use margarine for buttercream. It will be too soft. I had a cousin that used Smart Balance to make sugar cookies one christmas and when we all got together to bake our cookies, she couldn't figure out why her dough was too soft and sticky to roll out. I started asking a couple questions and lo and behold, no butter.

Gotta use butter.

Stick margarine can be used like butter. My mother always used it in her frosting. However, it will not have the richness of real butter...I use Land o'Lakes lightly salted. You need that touch of salt to counteract all the sugar. It will be worth it to use the real stuff. I've used Wilton's white coloring to whiten. I kind of like the idea of adding a mere touch of violet like the other poster suggested. I'm going to try that next time!