Crackle paint techniques vary and depending on what type effect you are trying to acheive and will help to determine the process you will want to use. Here are 3 popular techniques to consider.
The porcelain effect looks like old porcelain china. To achieve this effect, you will buy porcelain crackle glaze at a paint store or home improvement store. You can also buy this glaze at craft stores in smaller quantities if you are crackle painting something small, like a picture frame or lamp. Use a paintbrush to apply using thin zigzag strokes to get an even crackle.
Weathered crackle glaze will have larger cracks and give you the effect of old wood. You will need to buy weathered crackle glaze for this project, and the glaze with a paint roller as opposed to a paintbrush as used in the porcelain effect. This will give you a heavier coat that will give you larger cracks.
3. Glue Method
A really easy way to trying the crackling effect is to use regular white glue! Apply it with a sponge and finish with a topcoat of paint. The glue will keep the top coat from adhering to the top coat and it will crack giving you the crackle effect. This is good for a smaller project. Be sure to spray some clear coat on after it has dried to hold the glue on your piece.