How much does an Envelope Weigh?

At the beginning envelopes exist in the form of wrapped clay used by the Babylonians in 2000 BC, to protect important information such as accounts, loans or receivables and notes. Clay in its primary form was wrapped around the block that contained the protected information, and then baked in the oven. In the 10th century the paper started to be used and envelops were fabricated manually. The first envelope making machine was patented by Edwin Hill in 1845. A standard envelope weighs around 6.75 grams.