Prepare the walls before painting. Fill any holes or cracks with filler, allow to dry and use a medium-grade sandpaper to sand smooth. Also sand away any flaky paint to create a smooth surface to work on. Mask the edges of the walls, the ceiling and the skirting board with masking tape, and cover the floor and furniture with dust sheets in case of spillages.
Select a darker color for the base coat, and a lighter color for the top coat. Dark colors will create a suitably dingy effect, but will also significantly darken the whole room. The dingy effect is created by the painting technique rather than the color, so using light shades such as creams, grays and even white will still produce the desired effect.
Dip a paintbrush in the darker color and cut in the very edges of the wall. Use a roller to paint the rest of the wall for a smooth, even finish. Allow to dry.
Dip a brush in the crackling glaze and apply to the wall, ensuring your brush strokes all move in the same direction. Apply a thin layer of glaze for small cracks, a thick coat for larger, more obvious cracks. Allow to dry.
Take your clean paintbrush and use it to apply the lighter-color top coat. Ensure your brush strokes move in the opposite direction to the crackling glaze. If you applied the crackling glaze with horizontal strokes, apply the top coat with vertical strokes. As soon as the top coat is applied, you will see the crackling glaze begin to crack and create the effect of cracking, peeling walls.
Remove the masking tape and repeat the process on the next wall if desired.