Materials needed:

6 TBS. pure white vinegar
4 packs (1 oz.) unflavored gelatin
1 TBS. lemon extract

Instructions:

1) Bring vinegar to boil in a pan and add the gelatin, stirring until completely dissolved.

2) Add lemon extract and stir well.

Makes about 1/2 cup of mucilage. Store in a capped bottle or jar. Use paint brush to apply to envelope lip or flap. allow to dry. Moisten to seal.