Vegetable glues are easily and cheaply made, and get their adhesive qualities from the natural polymer chains of organic molecules found in plant starches. The starch comes from vegetables, plant roots, tubers and seeds. One of the most common vegetable glues is wheatpaste, also known as the papier-mache glue. Vegetable glues have many uses, from bookbinding and repair, to hanging posters and flyers on walls. Vegetable glues are archival materials used to frame and restore fine art on paper.
Things You'll Need
Buy a bag of specially prepared wheat flour from retail decorating stores sold for making wallpaper paste. The flour has been precooked, dried and packaged with extra binding ingredients added. Sift the flower and slowly add it to lukewarm water. Stir it with a cooking whisk until all lumps are dissolved. Use the glue right away, or store it in the refrigerator for a couple of weeks for later use.
Make wheatpaste vegetable glue from scratch using readily available, common white wheat flour from the ground-up seeds of the triticum vulgare plant. Get a bag from the local grocery store. Put a cup of water in a sauce pan on the stove, and heat it to about 200 degrees F. Drop 3 tbsp. of flour into just enough cold water to make a viscous mixture. Stir and add small amounts of water until the mix will flow easily.
Pour the flour dissolved in cold water slowly into the hot water. Stir it up continuously with a whisk while pouring. Turn up the heat to slowly bring the concoction to a boil. Stir until you have a homogenous, runny paste. Keep stirring until all lumps are broken up. Boil the glue for about five minutes to thicken and congeal it. Add 1 tbsp. of sugar to the glue after it thickens for better adhesive qualities.
Whiten the glue by combining two teaspoons of corn flour with 1tsp. of corn flour starch. Add half a tsp. of alum, the baking powder ingredient used in canning. Mix with 3 oz. of water to an even consistency. Heat to a boil, while constantly stirring with a wooden spoon or wire whisk. Substitute rice flour starch for the corn starch. Omit the wheat flour altogether for the whitest glue.
Use the same general recipe for making vegetable glue out of other plant starches. Adjust the water levels of the glue mixture until the consistency of wheatpaste is matched. Make vegetable glue from potato flour starch or use tapioca starch from the cassava plant. Reheat the glue and add water if it hardens during storage.
Boil the glue before storing to sterilize it.
Don't boil the glue too fast or it will discolor and turn brown.