https://scalablepress.com/?utm_source=google&utm_medium=cpc&utm_term=scalable%20press
I tried this outfit for a few things with good results, DTG output only required a PNG with embedded profile at 125 DPI at placed size. Super quality, price and turn around.
Has anyone here used them?
You should try Printseekers print on demand service. They accept more formats & print quality is quite good. Plus integration in ecom sites is fairly easy too.