There is a kind called commissioned production, and it is natural for the other party to know that your trademark will be affixed after processing.
However, there is another way. You buy other people's things and brand your own brand without permission, which is illegal and infringes on the exclusive right of registered trademarks of others.
According to the Trademark Law, any of the following acts is an infringement of the exclusive right to use a registered trademark:
(1) Using a trademark identical with or similar to its registered trademark on the same or similar goods without the permission of the trademark registrant;
(2) selling goods that infringe upon the exclusive right to use a registered trademark;
(3) Forging or unauthorized manufacturing of registered trademark marks of others or selling forged or unauthorized registered trademark marks;
(four) without the consent of the trademark registrant, the registered trademark is changed and the goods with the changed trademark are put on the market again;
(5) causing other damage to the exclusive right to use a registered trademark of others.