Shopify Personalization Not Reaching POD Partner

1. Property key mismatch (24%)

Your Shopify order line has property "Engraving text: Sarah" but Printful expects "custom_text". Check Printful app → Product mapping → Custom fields → verify the field name matches the property key exactly (case-sensitive). Rename either your line-item property or Printful's field to match.

2. Photo URL expired or 404 (17%)

Customer's uploaded photo was hosted on a temporary URL that expired before POD fetched it. Fix: use permanent storage (Shopify Files API, Cloudinary, S3 with long-lived signed URLs). Verify by opening the _photo_url property value directly — 200 = ok, 404 = expired.

3. Underscore-prefix property not forwarded (13%)

Underscore-prefixed properties (_photo_url, _dpi) are hidden from cart display but should still forward to POD. Some POD integration apps drop them. Check the app's docs — Printful reads all properties; Printify reads all; Gooten's older integration drops underscore-prefixed. Rename to non-underscore for those integrations, or upgrade to the current Gooten integration.

4. DPI too low, POD auto-rejects (11%)

Customer's uploaded photo is 400×400 pixels (72 DPI at the intended print size). POD's minimum is 300 DPI, which means 1500×1500 minimum for a small mug print area. POD auto-cancels the order and emails the merchant. Fix: validate DPI at upload time on the storefront:

function validateDPI(imageFile, printAreaInches) {
  return new Promise(resolve => {
    const img = new Image();
    img.onload = () => {
      const dpi = Math.min(img.width, img.height) / printAreaInches;
      resolve(dpi >= 300);
    };
    img.src = URL.createObjectURL(imageFile);
  });
}

5. Wrong POD product ID mapped to variant (9%)

Shopify variant "White mug 11oz" is mapped to a Printful product ID that no longer exists (Printful deprecated the SKU). POD receives the order, can't find the product, ships a default template blank. Fix: audit Printful → Sync products → find deprecated SKUs → remap to current equivalents.

6. Character set unsupported (8%)

Customer typed Japanese in the engraving field. POD's font doesn't include Japanese glyphs. Rendered file shows blank boxes ("tofu"). Fix: (a) filter Japanese input if your POD doesn't support it, or (b) pre-render the file client-side to PNG with a Japanese-capable font and submit the PNG instead of text+font. See markets multi-language options.

7. Print file spec mismatch (7%)

Your print file has 0mm bleed; POD requires 3mm bleed. POD returns "file rejected" email; order stalls. Fix: generate print files matching each POD partner's spec sheet (Printful: 3mm bleed for apparel, 5mm for canvas; Printify: 5mm all; Gelato: varies by warehouse). Automate via a print-file generator that reads the POD spec + adds correct bleed.

8. Webhook delivery failure (6%)

Shopify's orders/create webhook to the POD app failed and retries exhausted. Check Shopify Admin → Settings → Notifications → Webhooks → click each webhook → verify last delivery status. Failed webhooks retry for 48h; after that they're dead. Fix: ensure your POD app's endpoint returns 200 quickly (queue the payload, don't process sync).

9. Multiple integrations conflict (5%)

You have both Printful's native app AND a custom Zapier flow both forwarding orders to Printful. Order lands twice; Printful ships one, cancels the duplicate. Fix: remove the older / duplicate integration. Audit all webhook subscriptions via webhookSubscriptions query.