Aleene's Original Tacky Glue can create crackled effects on surfaces. Here is how to create a crack effect using glue:
Paint the object with a base coat of acrylic paint. Let dry.
Brush an abundant layer of Tacky Glue over the dried paint in the areas you want to crackle. Let the glue set until firm and tacky but not completely dry.
While the layer of glue is still sticky, brush the same color of paint or a contrasting color over the glue, brushing only once instead of back and forth, as that could hinder the crackling process.
As the paint and glue dry, they will naturally crackle. Let dry completely.
Protect your project with your favorite Aleene's Acrylic Sealer.