T-shirt Designer

I am looking for a designer who is capable of doing the most simple text based designs to much more complex designs. You will get at minimum 3-5 design requests per day with the possibility of more coming down the road It is important that designs are delivered on time and in .png format for us to upload to our tshirt site. If you need dimensions or anything please let us know. Please show examples of designs previously done, if you have done shirts before that is a plus.

If you have experience with TeeSpring or similar sites, then please let me know in your response.

Timeproof is a must.

Thanks!