Sams Club has sandwich croissants that I am fond of. They come in a clear container with a 9x15 lid. The lid is perfectly clear tough plastic with a slightly indented border. Cut around the lid leaving the indent and you have a window for a tarp. We bought some fried chicken from Krogers with a similar lid which gave the idea, so many more and different size lids must be available.
To install just cut a hole in a tarp the size of the window. Use strong double stick tape on the indented border of the window. Stick the window in the cut hole. Use strong colored duct tape for a pretty frame surround and to strengthen.
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