We work for a plant that manufactures Jams & Jellies and we often obtain our fruit (cherries) in square 4 gallon / 15 liter pails,100+ at a time. As they are square and white, they place right up to one another and reflect the heat of our California sun shine. We have some that have been right out in full sun for 3 summers and just now are starting to show some evidence of getting brittle. If you wish manufacturer info we can get it for you. All the best, Michael & Paul Hilmar, CA