Near the bottom of
THIS page from the LDS Distribution Services website it reads...
Stationery Orders:
Please use the Tithing and Offerings Envelopes and Other Stationery Items
Order Form for ordering envelopes with the Bishop's or Branch President's name and address. The Tithing and Other Offerings slips are automatically sent with each order of envelopes. To order these items send, call or fax your order form to:
Salt Lake City Distribution Center
P.O. Box 27647
Salt Lake City, UT 84127-0647
Salt Lake Area: 1-801-240-3800
U.S. and Canada: 1-800-537-5001
Fax: 1-801-240-3685