Bento Placemat Lunch Bag Royal Blue/Orange Brown/Silver. The FlatBox Bento Lunch Bag is â??The Placemat That Carries Your Lunchâ??. FlatBox Bento Lunch Bags are 100% machine washable and the patented unique design easily unzips to a placemat, providing you with a clean and healthy eating surface. FlatBox is the only lunchbox that effectively addresses consumers' growing concerns of food allergies and cleanliness.