This is a great technique! Crackle finish with "Elmers" glue! It is so easy ..1.paint your surface with acrylic paint(Dark color)..let dry, 2.paint on a layer of glue (fairly light to medium) then 3.while the glue is still wet, paint on a medium coat of contrasting Light color acrylic paint, speed drying with heat tool (not too close!) .
Have fun and try different colors and different thicknesses of glue and contrasting paint to get a variety of looks!!