[Source] Standard job envelopes

To all:

I am trying to find standard job envelopes that have blank backs.
These days, all envelopes are sold with “payment schedules” on their
backs, where I normally keep track of all the operations I perform on
the contents. Does anyone out there know where I can obtain this type
of job envelope? The front side with various printed is
OK; not looking for completely blank envelopes.

Chris van Laer