Glue Gun Wax Sticks
While nothing beats the romance of using a wax furnace to prepare one seal at a time, when you have a stack of envelopes to get through, you need a faster method. Enter glue gun sealing wax! It fits into a standard half-inch glue stick (preferably with a low-temp setting), and once it warms up, you can make a bulk mailing feel deluxe and special in no time at all.
Each pack of six wax sticks will create seals for approximately 50-60 envelopes.