Our four non-profit tax preparation sites give every taxpayer a federal and/or state pre-addressed envelope (with a Staples label) to send in their payments. They love the extra courtesy and we like helping them at a reasonable cost.
These envelopes are a good quality for a good price. As a church we are oriented toward stewardship and are willing to seal the envelopes with water rather than go to the expense of pull and seal. These are worth the investment!