Here's the recipe for the envelope glue I used in the Daisy card gift set. It smells pretty bad when you're making it, but has no scent other than a slight hint of the "flavoring" you use. I was amazed at how fast it dried. It dries shiny, so it still looks wet, even though it isn't.Took about 5 minutes to dry. I was a little worried about how ripple-y the glued edge was, but I stacked them on top of each other and put them under a couple of HEAVY books (Strong's Concordance was one, for those of you who know what that is - HUGE!) In the morning they were flat and crisp.
6 T. white vinegar
4 packets Knox unflavored gelatin
1 T. extract of choice: vanilla, peppermint or cinnamon are good choices
Put vinegar into a small saucepan over medium heat. Sprinkle gelatin evenly over the surface. Stir with a wooden spoon until the gelatin is fully dissolved and the mixture comes to a boil, about 2 minutes. Remove from heat and stir in extract. Cool slightly before brushing a thin, even layer onto your envelope, being careful not to extend it past the area where the flap overlaps the envelope. Allow to dry. Clean brush well with warm water & dish soap.
Keep unused portion in an airtight, leak-proof container. It will "gel", so you will need to reheat gently in warm water to melt for reuse. (You could probably microwave it on a low power, too.)