Have you noticed that your tiniest ecommerce items, which used to be shipped in a box, are now arriving in a padded envelope? WSJ reports: Amazon is trying to ship each order in one correctly sized package instead of multiple boxes, responding to rising shipping costs and consumers' concern about the environmental impact (Editor's note: the link may be paywalled) and general nuisance of all that cardboard. That means adding bubble envelopes, tweaking algorithms and negotiating with manufacturers to make smaller packaging specifically for online sales, not store shelves. [...] This year, Amazon added machines in its warehouses that create padded mailers on demand to fit smaller items, all of which used to go into the company's smallest-sized box. Almost half of all of Amazon's products fit into the new mailers and poly bags, says Kim Houchens, director of customer packaging experience. Her team has been working to improve algorithms that help decide which size box and how many items should be packed together in each shipment. The algorithms use machine learning to test out new combinations -- for example, shipping a breakable item in a smaller box with less cushioning. The algorithm can scan customer reviews and other data to see if it worked and adjust as needed.