Dear EarthTalk: Are any major brands of disposable tissues, paper towels, napkins and toilet paper yet using recycled content and chlorine-free bleaching? -- Sylvia Comstock, Montpelier, Vt. Dear ...

With a few notable exceptions, the majority of objects removed from a 3D printer bed are fashioned using plastic. But plastic has a nasty habit of ruining our environment at the end of its useful life ...

We’ve seen all sorts of 3D-printers on these pages before. From the small to the large, Cartesians and deltas, and printers that can squeeze out plastic, metal, and even concrete. But this appears to ...