I've used the old-fashioned speckleware for years. As we've been trying to eliminate use of plastic, and I keep breaking glass pitchers, I've just resorted to buying a second speckleware coffee pot to make my iced tea in - one to hold, while the other is being cleaned, and storing tap water to age out the chlorine and flouride. When it's warm enough, I even make sun tea in the darker coffee pot. This led me to using a small dark speckleware pan to thaw and heat my frozen food in the sun - a bowl of frozen chili is actually hot enough to eat after a few hours! I haven't tried using the red or lighter blue pots & pans in the sun. This is without even using a solar oven. If it's windy, or not real warm outside, I kind of cheat, and enclose the pot/pan in a plastic oven bag, and set it on a coffee can I painted black. I'm really trying to eliminate plastic, but I just can't find a glass enclosure large enough. I seem to get better results when the sun is NOT at it's highest in the summer - when it's lower, more sunrays hit the side of the containter. I have used an old camp mirror set up behind the pot, when the sun is pretty high, to reflect more light onto the side. Any meal heated this way eliminates scorching, and never dries out - the moisture is wonderful (especially when I've indulged and used Arby's coupons to buy multiples) for sandwiches - the bread is always soft, but never soggy. For Christmas, when I have more food than my fridge will hold, I use my honkin' big speckleware pots to store food outdoors - the thin walls cool very quickly. I learned years ago that a particular parson's table set over each of these pots, with their lids turned upside down, with a planter on top of the table, will keep night critters at bay.