What are the world's best websites to design a t-shirt online?

Zazzle does well on custom printed.  My son used another site and they printed the jpeg about 4" x 4" without warning (waste of money).  If Zazzle thinks the image will become pixelated they will warn you, but not automatically decide no one would ever want something to look like 8-bit art (which was the goal to cover the front of the shirt with not a stain sized image).

If You are interested in design you own T-Shirt and looking for the perfect tool to do so. I hightly recommnd My Favorite store http://inkyrobo.com They provides online t-Shirt design software, where you can customize your T-shirt by adding text, photo. It's fully responsive and highly user friendly tool/software that makes online t-shirt designing a sheer fun for your customers. See the live Demo: http://inkyrobo.com/jQueryTshirtTool/LivePreview I would like to answer a few questions that may arise in your mind: There will be no need to invest anything. That’s right! Anyone with an idea for a T-shirt can ‘launch a campaign’ by creating it in our design studio and market it to relevant groups and sell them via our platform. I repeat....There is no need to invest any money. At no point in the My Dream Store experience will you have to spend any money! (Of course if you want to market your Tee, there may be advertising costs involved. But that is up to you! Everything else — manufacturing the exact sizes, flawless printing, delivering the t-shirts to the buyers all over India will be taken care of by our team. After the campaign is over, we wire the profits to the campaigners. It has been proved time and again that My Dream Store is a viable platform for making big money online completely risk free. This is the time for you to take the leap and give it a shot.

We spent a LOT of time building up our Design Studio at http://UltraPress.com and we are proud to suggest it for your custom apparel designing efforts. We have a clipart library with 1,000's of options, the ability to upload your own artwork and more! Check us out and let us know what you think - we love feedback as we are constantly striving to offer the best custom apparel ordering experience out there!

We also have taken a lot of energy and effort into our website, as a graphic designer myself, I want the online experience to be a good one. Take a look at http://MakeATeeOnline.comHopefully you will like this site and I can promise you that our customer service is the best around.TIA