How would you do these strips on a cake? (especaily in black!) Do you need an extremly steady hand? (I know mine would come out all uneven) Is there a secret to them?
if you want to pipe it, i would cut a guide out of waxed paper to wrap around the cake, then pipe, you still need a nice steady hand and using ribbon would just be easier.
If you hold a toothpick in one spot then spin your turntable you would have a nice even straight line to follow. I ain't brave enough to do it directly with icing.