A regular, #10 envelope with less than 12 sheets of printer paper in it will be around 1 ounce | A larger envelope with between 12 – 25 sheets of regular paper in it will be around 2 ounces |
A smartphone with a case is about 8 ounces | An empty, 8oz ceramic coffee mug weighs around 12 ounces |
A Swingline brand stapler is about 16oz, or 1lb |