Lenticular postcard

The most critical factor is the LPI (Lines Per Inch) of the lenticular lens. For postcards, a range of 75 LPI to 100 LPI is standard to balance image clarity and the depth/motion effect. You must also specify the material thickness (typically 0.35mm to 0.9mm) and the printing process, which should ideally be UV offset printing directly onto the back of the lens for the highest durability and alignment precision.

Lenticular postcards generally offer three effects: 3D Depth, Flip (changing images), and Animation/Motion. For souvenirs, 3D Depth is most popular, while for promotional marketing, a 2-phase or 3-phase Flip is more effective at conveying a message. Ensure the supplier provides a digital interlacing proof to verify that the 'ghosting' (image bleeding) is minimized before mass production.

Since postcards are often handled by children or sent through international mail, they must comply with REACH or RoHS standards for non-toxic plastics (PET or PP). For the US market, ensure the materials are BPA-free and phthalate-free to meet CPSIA requirements. Additionally, verify that the edges are die-cut smoothly to prevent paper cuts or sorting machine snags.

Request a physical sample pack to check for alignment accuracy; if the lens and print are misaligned by even a fraction of a millimeter, the effect will be blurry. Look for suppliers who use high-quality PET material rather than cheaper PVC, as PET offers better transparency and UV resistance, preventing the postcards from yellowing over time.

The primary risk is image ghosting or blurring due to poor interlacing software or low-precision printing. Another risk is warping during transit; lenticular sheets are sensitive to extreme heat. To mitigate this, ensure the contract specifies temperature-controlled storage or heavy-duty moisture-proof packaging.

Focus on tooling and setup costs. Lenticular printing requires a high initial setup for 'pitch matching.' Negotiate for a refund of the mold/setup fee once your cumulative order volume reaches a certain threshold (e.g., 5,000 units). Always request a pre-production sample and use Trade Resources or Secure Payment services provided by the platform to protect your funds.

Lenticular cards are heavier than standard paper postcards. For large volumes, Sea Freight (FCL/LCL) is most economical, but for time-sensitive promotions, Air Express is preferred. Ensure the HS Code (typically 4911.91) is correctly declared to avoid customs delays. For EU buyers, ensure the supplier can provide an Electronic Advance Data (EAD) for smooth VAT processing under IOSS.

Always verify the supplier's Audit Reports on Made-in-China.com to confirm their manufacturing scale and history. Use Escrow-based payment methods where the balance is only released after you receive the Third-Party Inspection (TPI) report confirming the 3D effect meets the approved gold sample.