Custom t-shirt business

Walekumussalam,

If the situation is exactly as described—namely, that you do not keep the shirts in your possession beforehand, but after a customer places an order, a contracted printing company or manufacturer prints and produces the requested shirt, and you clearly inform the customer in advance that the shirt will only be produced after the order is placed (Print-on-Demand), while all the essential specifications of the shirt, such as its size, color, design, fabric, price, and other relevant characteristics, are determined and known beforehand—then, according to the Hanafi school of Islamic jurisprudence, this arrangement may fall under the contract of Istisnāʿ (manufacturing contract).

Istisnāʿ is a contract in which a person requests another to manufacture an item according to agreed specifications. The Hanafi jurists have deemed this contract permissible due to necessity and established commercial practice, provided that its Sharīʿah conditions are fulfilled. Therefore, if all the specifications of the shirt are clearly defined, the transaction is conducted with mutual consent, there is no deception, misrepresentation, or concealment of facts, and the finished product conforms to what was agreed upon, then such a business is, in principle, permissible.

However, if the true nature of the transaction is concealed, the goods or their specifications are misrepresented, or any condition is included that renders the contract invalid according to Sharīʿah, then such a transaction would not be permissible.

Radd al-Muḥtār explains the definition of Istisnāʿ and its conditions, stating that it is a request to manufacture a specific item in a specified manner, and that the genus, type, quantity, and specifications of the item to be manufactured must be clearly defined.

(Radd al-Muḥtār ʿalā al-Durr al-Mukhtār, "Maṭlab fī al-Istisnāʿ", 5/223–224, Dār al-Fikr).

Likewise, Badāʾiʿ al-Ṣanāʾiʿ mentions the conditions for the validity of Istisnāʿ, including that the genus, type, quantity, and specifications of the manufactured item must be clearly known, and that such a transaction should be one that is customarily practiced among people.

(Badāʾiʿ al-Ṣanāʾiʿ, Kitāb al-Istisnāʿ, "Faṣl fī Sharāʾiṭ Jawāz al-Istisnāʿ", 5/3, Dār al-Kutub al-ʿIlmiyyah).