Use silicone for mousses, entremets, inserts, and baked mini-cakes. Choose plastic for chocolate, sharp details, and designs requiring perfect definition.
Silicone offers flexibility, clean release, and even temperature distribution—ideal for creamy or frozen textures. Plastic is better for professional chocolate work, fine textures, and molds where structure must remain perfectly rigid. The choice depends on the dessert’s composition, finishing technique, and expected level of visual precision.