Fish Glue

This technique works well with water-based paints like
Apply the first coat of paint to create the undercoat. This is the colour you will see when de crazing occurs. Once completely dry, apply fish glue with a small paintbrush. Apply the Fish glue only where crazing is desired. The thickness of the coat of Fish glue will determine the size of the cracks. The thicker the glue the bigger the cracks. If a finer crack is wanted, the glue may be diluted with warm water to thin it down before applying it.
Once the glue is partially dry, apply rapidly a coat of paint. Crazing will start almost immediately. Results may vary depending on the paint's pigment concentration.

To accentuate the crazing apply a tinted oil or a Buffing wax.
See Arabic gum for another crazing technique.