Troubleshooting Print Price Engine

The issues merchants actually hit, roughly in order of frequency — with fixes.

The calculator isn't showing on a product#

• The product needs a recipe assigned — directly, by variant, or via a linked collection. No recipe, no calculator (by design).
• Confirm the block is added to the product template in the theme editor.
• If the recipe is linked via a collection, check the product is actually in that collection.
• Variant-specific recipes only render for that variant — switch variants to check.

The quote is right, but checkout charges the base price#

The cart transform isn't active. Open the app dashboard and complete the Activate Engine step — this registers the Shopify Function that applies calculated prices at checkout. It's step 4 of Getting Started and the single most common setup miss.

Customers can't add to cart#

• A required option is unanswered — the calculator blocks add-to-cart until every required option is filled.
• Dimensions are outside the recipe's min/max bounds — the inputs won't accept out-of-range values.

The price looks wrong#

Work through the formula in order (try the demos in How It Works):

1. Ingredient costs — right cost unit? A "$450 per roll" entered as "per m²" will be spectacularly wrong.
2. Roll dimensions — for Per Roll / Per Meter units, the roll width and length drive the per-m² derivation.
3. Markup — applies to variable costs only; fixed costs pass through at cost.
4. Wastage buffer — adds to each dimension before area is costed.
5. Discount tier — check which tier the test quantity lands in; discounts touch variable costs only.
6. Rounding — a 0.99 rounding setting changes final digits by design.

A cart quantity change didn't change the price#

It did — at checkout. The cart page may show the original line price, but the cart transform recalculates from the live quantity during checkout, tier discounts included. Test it through to the payment step before concluding otherwise. See How the Price Reaches Checkout.

Artwork uploads aren't arriving#

• Uploads must be enabled on the recipe.
• The file link is attached to the order's line item properties — check the line item detail on the order, not the order notes.

Usage seems off#

Only paid orders containing an engine-priced line item count, once each — drafts and abandoned checkouts never do. The Billing page shows the live count; it resets on your monthly cycle. See Plans & Billing.

Still stuck?#

Email info@lubbelabs.com with your store URL, the product, and a screenshot of the recipe — we usually reply within one business day.