When evaluating porcelain quality, focus on translucency, whiteness, and resonance. High-quality porcelain should have a water absorption rate of less than 0.5% to ensure durability and prevent leaking. For decorated vases, verify that the glaze is lead-free and cadmium-free, especially if the items are intended for markets with strict health regulations like the EU or USA. Additionally, check the firing temperature, which should ideally be between 1200°C and 1400°C to ensure the material is fully vitrified and chip-resistant.