Michigan taxpayers should think twice before stapling state tax documents and consider other options for fastening paper together prior to mailing, according to the Michigan Department of Treasury (Treasury). Each year, Treasury receives and processes more than 1.3 million pieces of U.S. Mail at 51 post office boxes and two ZIP Code mailboxes. For every staple used, mail operations staff members must remove and recondition affected documents before scanning and processing, slowing down individual income tax refunds and other services.Taxpayers are encouraged to use binder clips, paper clips and rubber bands for fastening state tax documents together. Staples should only be applied where tax form instructions advise to use them.