I went to USPS site to order Free Priority Shipping Supplies for shipping Ebay junk. I couldn't find the tape, so, I sent then an Email. Here is the response I got. Rumor has it free boxes are next. I just ordered a truck load. Better stock up if you need them.

Dear Mark,

Thank you for contacting us regarding USPS shipping supplies. Priority Mail
and Express Mail Tape is no longer offered online or through our customer
service number. Many of the boxes the Postal Service provides have a
self-sealing transfer tape, and therefore should not require a tape item to
be sealed. This decision will enable the Postal Service to reduce costs
associated with packaging supplies, and will help the organization maintain
its commitment to financial responsibility. Cost curtailment initiatives
like this one are undertaken with the understanding that lower costs help
keep mailing rates low for Postal customers. The tape items had been
intended to help customers identify packages as Express Mail or Priority
Mail. The Postal Service has many alternative products that serve a similar
purpose, such as decals and labels. These items remain available. You may
want to use the following: for Priority Mail, Label 106 or Label 107-R.
For Express Mail, Label 127-R. At this time, the Postal Service offers
tape for sale only at local Post Offices.