I Have design T-shirt for
1) Teespring
2) BustedTees
3) NoiseBot
4) T-Shirt Hell
5) GMtee
I have complete understanding about each website and there different requirements to upload T-shirt
Please take a look of my portfolio in the Below dropbox link of respective clients and works are provided for your evaluation.
https://www.dropbox.com/sh/0j1gma0tmarqxwb/AAAGXRFcvmdvvIe8Wv_iuB9La?dl=0