The best way to ensure your salad dressing is gluten free, or dairy free, egg free, vegetarian...etc...is to make it yourself. You can make salad dressing cheap and easy, saving money and preservatives from those bottled, overpriced things on the supermarket shelf. Also you won't be wasting any plastic that will just fill landfills, and you only have to make as much or as little as you need. It's really a no-brainer. Add to the fact that your guests will be so impressed at the gourmet touch to your dinner...you don't have to tell them how easy it is.