I use the foam egg cartons because my egg customers return the curtains to me and I can wash them. I cannot wash the pulp ones, they provide less protection, and their overall use life is far shorter. I do occasionally purchase the pulp ones, but they also don't allow for size variation and the eggs themselves as well as the foam cartons do. Does enjoy pulp because once I'm done using them for my eggs, I add them to my composte pile. I love that the pulp cartons are so eco-friendly. One of the best things about them is that when they have reached the end of their egg-life, I can tear them up and mix them with chicken waste and other compost. The addition helps make the compost break down faster, and the kids love the bit of wanton destruction.�or whatever. Do what you will. As for size variation: I have a very mixed flock, which includes chickens of all sizes, ducks, and turkeys. When new, the pulp cartons are hard, and cannot flex to accommodate larger eggs, strangely-shaped pullet bullets, or that �my hen had a crappy morning� double-yolker. However, once the older pulp cartons are broken down enough to accommodate the larger eggs, they�re usually damaged to the point of over-flexibility, and are in danger of ripping apart if I load them down with the heavier duck or turkey eggs. The solution there is to purchase different size pulp egg cartons - but to make that economical, I�d need to order them in volumes of 250 or more. I don�t have the space for that, nor the desire to sort them into piles when my egg customers return them. And if I made the kids do it, the whining would be terrible. So, I prefer to stick to the foam cartons, which wash easily, have more �give� around odd-shaped/sized eggs, and have a longer over-all life. More use means I can defer the cost of the cartons over a longer period of time, which helps keep my egg prices low. ($2-$3 cheaper a dozen, then the farmer�s market just down the street.)