Manage Shared Fabric Inventory Across T-Shirt Variants in Shopify

An apparel store sells several T-shirt variants made from the same roll of fabric. Each size uses a different amount. If the store treats each variant as having a separate fabric allocation, the displayed sellable quantities can overstate what it can actually make.

Illustrative scenario: The quantities below show how to model the workflow in Soply. They are not results from a real merchant.

The inventory problem

The store has 24 meters of fabric available to use. A small T-shirt consumes 0.7 meter, while a large T-shirt consumes 1.1 meters.

These figures describe two possible uses of one 24-meter pool. They cannot be added together. If 10 large T-shirts consume 11 meters, 13 meters remain and the fabric then supports at most floor(13 ÷ 0.7) = 18 small T-shirts, assuming no other inventory activity.

Model the scenario in Soply

1. In Inventory rules, choose a mode that includes raw materials.
2. In Raw Materials, create an app-managed material named, for example, Cotton fabric. Set its unit to meters and record the actual opening stock.
3. In the material's Product Usage, bind the small and large Shopify variants to the same material. Set Consumption Per Unit to 0.7 m and 1.1 m respectively.
4. Check the material's Available to use and each variant's calculated availability. If other products also use this fabric, bind them to the same pool with their own per-unit usage.
5. Check that cart and checkout validation is active, then test a permitted quantity and one above the calculated limit.

What the store should verify

The example assumes fabric is the only limiting material. Buttons, packaging, location settings, existing orders, and the selected order timing rule can lower the actual quantity. After a relevant order or stock adjustment, inspect the material's available quantity and snapshots before comparing the variants again. Also check whether either variant has Allow selling when raw material is insufficient enabled, because that changes its sales policy.

For the exact controls, see Create an app-managed material, Bind product variants, Calculate shared material availability, and Configure purchase validation.

If a buyer places several fabric-based products in one cart, follow the mixed-cart conflict case to check their combined requirement.