Head on over to the Shipping page to generate/download/print scan sheets.
The Post Office or your mail carrier will ask you to print out a SCAN Form (also known as a shipping manifest) if you ship a large number of packages at once. This single sheet of paper lists everything you're sending and allows the postal system to receive the items in bulk much faster.
The most important thing you need to know about scan forms is what orders can be included on your manifest. When you select the “Create Scan Form” option, all orders with a ship date greater than or equal to the current ship date can be included. The manifest will be dated by the latest package in the grouping. Therefore, you will need create your scan form on or before the cutoff time at 8 pm PST or 9 pm PDT each day. After the cut off, the next "ship date" begins and the new packages will cause the Scan Form date to bump up leaving older packages off the manifest. See full list of time zones below for cut off times.
And to reinforce again -- orders with a ship date in past can NOT be included on your manifest.
Remember that you can provide the Post Office with multiple scan forms if you need to print a scan form at the time cut off and continue shipping packages. An alarm reminder will help you if you tend to ship more often in the evening or over the weekend.