Creating a crackled or aged finish on porcelain sculptures is a popular technique among artists and collectors who appreciate the vintage aesthetic. Here are the most common methods to achieve this effect:

1. Crackle Glazing: A specialized crackle glaze is applied to the porcelain before firing. As the piece cools, the glaze contracts at a different rate than the clay, creating fine cracks.

2. Thermal Shock: Rapid heating and cooling during firing can induce natural cracks. This method requires careful control to avoid damaging the sculpture.

3. Chemical Aging: Solutions like vinegar or ammonia are brushed onto the surface to create a weathered appearance. This technique is often paired with staining for added depth.

4. Dry Brushing: Lightly brushing acrylic paints or oxides onto the surface mimics the look of aged porcelain, highlighting textures and crevices.

5. Faux Aging with Crazing Mediums: Commercial products like crackle mediums can be applied post-firing to simulate age without high-temperature processes.

Each technique offers unique results, allowing artists to customize the level of aging and crackling to suit their vision. Experimentation is key to mastering these methods.