Combine three parts boiling water with one part flour and a half part sugar in a bucket.
Use a metal spoon to stir the mixture.
Load up a paint brush with the wheat paste and apply the paint to the wall using even strokes.
Prepare a flat surface or a table -- the floor also will do -- with a sheet of plastic or a drop cloth to protect the floor from splattered or spilled wheat paste.
Lay the piece of graffiti onto the flat surface and gently apply the paste to the back of the piece.
Roll the paper up onto the wall, starting at the bottom and moving up. Smooth out bumps creases and air bubbles along the way.
Seal the piece of graffiti on the wall by applying a top layer of wheat paste over the graffiti.
Allow the paste at least one day to dry completely.