Crackle glazes are a simple idea, they attempt to re-create the effect of old varnish that cracks and crazes over time.
The way they work is simple the water-based varnish dries quicker than the oil-based one, and the movement from the underlying layer, which is still drying, causes the top layer to crack.
Crackle glazes consist of a base coat and a top coat, I have used all of the available crackle glazes in my time, oil based varnishes with a water based top coat, made from animal glue or an acrylic varnish, the oil based crackle glazes were often difficult to control owing to the critical temerature range they worked under, also you could not control the size of the cracks.
I now use a purely acrylic crackle glaze that I have found to be wholly dependable and consistent.
You can gauge how large or small you want the crackle to be by making the top coat thicker or thinner depending on what you want to achieve.
Here are some example of crackle glazes, some of these have had added an ageing glaze to give an older appearance to the gold leaf, please note in all these examples and others that follow we use only composition gold leaf, this is great for people starting out who don't want to spend a fortune of genuine gold leaf, of course if you do want to spend money on real gold leaf you can of course do so, you will get exactly the same effects.
You can apply my crackle glaze to almost any surface, here you can see the effect on a paper surface.
You can also apply it to a painted surface or onto wood, stone, porcelain, glass or metal.
I cover all the process's in detail in the two gilding manuals which are available at no charge from the downloads page.