Although a plastic bag is perfect for small pin striping jobs, piping large volumes of chocolate is best done with a sturdy canvas pastry bag. Be sure to get one that is lined with plastic, as any chocolate will permanently stain regular unlined pastry bags. Only a sturdy canvas bag can withstand the pressure required to forcefully expel a clogged tip filled with ganache.
When filling the pastry bag, be careful not to overfill it. Tightly fold the open end several times and apply pressure with your hands. One hand secures the rolled top and the other guides the tip. The warmth from your hands will affect the viscosity of the chocolate, so don't be surprised if the chocolate ends up more runny as you empty the bag.
