Porcelain decal

The primary difference lies in the firing temperature and durability. On-glaze decals are applied on top of the fired glaze and fired at 750°C to 850°C, offering a wider range of vibrant colors but lower scratch resistance. Under-glaze decals are applied to the biscuit and covered with glaze, fired at 1200°C to 1350°C; these are extremely durable, microwave-safe, and dishwasher-safe, though the color palette is more limited due to high-heat stability requirements.

For B2B buyers, compliance is non-negotiable. You must ensure the decals are Lead and Cadmium free, especially for the interior of drinkware. Request FDA (USA), LFGB (Germany), or EU 84/500/EEC compliance certificates. Always ask the supplier for a third-party lab test report (such as SGS or Intertek) specifically for the finished product after the decal has been fired onto the porcelain.

To ensure high-resolution printing, suppliers typically require vector files (AI, CDR, or PDF). The resolution for raster images should be at least 300 DPI. It is critical to specify Pantone Color Bridge codes to minimize color deviation during the screen printing or digital printing process. Always request a pre-production sample to verify color accuracy after firing, as colors change significantly in the kiln.

Screen printing is the industry standard for large volumes (MOQ 500+), offering better color thickness, metallic effects (gold/silver), and lower unit costs. Digital printing is ideal for small batches, complex photographic designs, or rapid prototyping, as it requires no film or screens, though the cost per sheet is significantly higher and metallic colors are harder to achieve.

Color shifting is a common risk due to kiln temperature fluctuations. You should negotiate a 'Golden Sample' agreement, where one signed sample is kept by you and one by the supplier. Explicitly state in the contract an acceptable Delta E (color difference) range. For large orders, use Made-in-China.com's inspection services to verify color consistency across different production batches before final payment.

Decals are sensitive to moisture and pressure. Ensure the supplier uses moisture-proof PE bags for vacuum sealing and places them between thick corrugated cardboard sheets to prevent bending. For sea freight, insist on palletization with shrink wrap to avoid humidity damage. Clearly label the outer cartons as 'Keep Dry' and 'Do Not Fold'.

To mitigate financial risk, utilize Secured Trading services on Made-in-China.com, which holds the payment until you confirm receipt and quality. Avoid using non-traceable payment methods. For the first order, a 30% deposit and 70% balance against the Bill of Lading (B/L) or after a successful pre-shipment inspection is the professional standard.

When providing custom artwork, ensure your purchase agreement includes a Non-Disclosure Agreement (NDA) and a clause stating that the intellectual property belongs solely to the buyer. This prevents the supplier from selling your proprietary designs to other clients or displaying them at trade fairs without your permission.