Wheatpaste is the glue for postering in the streets. It is mostly composed of flour and water, and will keep your posters up for as long as a year.
Recipe to make 2 litres of wheatpaste:
- 9 cups of water
- 3 cups of white flour
- glue or matte modge podge (optional)*
Start to heat the water at a medium temperature, stirring in the flour in small amounts with a whisk to avoid clumping. You should be adding flour and heating the water for about ten minutes, whisking throughout. Before it gets to a boil, take it off the heat and check the consistency; you are looking for something like watery glue, keeping in mind that the paste will significantly thicken as it cools. You may have to stir in more water if it is too thick, which would cause it to be opaque.
When the paste is ready, you can transfer it to milk containers to look inconspicuous in the streets, and just pour it onto a brush. Thoroughly wet the smooth surface you want to stick the poster on, have someone else firmly place the poster and smooth out any creases, then go over the top of the poster with more wheatpaste. Brush out any drips, and paste under any edges that aren’t sticking. The paste should be warm when used.
*To make your posters stay up for longer, you can add an adhesive as well. After taking the paste off the heat, add 1 1/2 cups of cold water to cool it so that the adhesive won’t clump, then stir in another 1/2 cup of flour. You can add 2-3 containers of white glue, or a similar volume of matte modge podge you can rack at art stores. Stir it in, then reheat the paste a bit before going out.