This is My Favorite Decorating Bag! This is what we use every day at Classic Cakes. It is heavy duty & will last you a very long time, if not forever. Can be cut to fit just about any size tip. I recommend having more than one of these in your Cake Kit! 
 
18" Fabric Decorating Bag
Very Flexible, Tough Polyurethane coated polyester
 
 
Wash with hot soapy water & hang to air dry.