As you probably know, my wife and I handle all Naolito.com products and orders personally. That means that we're able to make sure that everyone get the quality of products and service we'd like to receive.
T-shirts and other products like metal posters, home accesories, etc. are a bit more complicated though. We've offered them in the past, but being as small as we are, it's preferable to rely on one of the big companies I've worked in over 12 years of career doing t-shirts to guarantee you get the best experience possible.
These are 100% trusted sites, I've worked with them over a decade and that's the reason I trust them to handle my designs.
In any case, I'm always interested to know your experience to keep offering the best experience possible.