Dear Hiring Manager,
If I have understood your requirement correctly, then You are looking for an online website on which you can provide your customers with facility to design their own Tshirts and you will do the custom printing and ship the Tshirts to them. I have already completed similar projects in past hence I am pretty much sure I can do the task for you as I have a versatile team of web-designers and developers who can assure you the best turnaround and satisfaction on this project.
Kindly consider my offer and do let me know for any questions regarding the same. I will be more than happy to acknowledge them all and will come up with the best solution possible. Looking forward to hear from you soon.
Best Regards,
Rahul Dhangar