What's the photo format (jpg, PNG, ...)required for professional printing? What's the highest resolution that can be printed? Is there any standard size limited for printing? Thanks.

Jpg is the accepted standard file. PNG can be converted I'm sure. PDF is really todays standard. Resolution is up to 4800 dpi, but you don't see over 600 dpi normally. It's the dot screen that matters, which is normally 200-240 lpi. If your file is under 200 dpi, you'll see dots. How big do you want it? They can stitch billboards.

jpg is the most common format. We can print from jpg, png, tif. We can also print booklets and brochures from a pdf file however our online software doesn't support it. 300 dpi is the standard for 90% of the photo printers out there. Sizing a file prior to sending is not required. Our software can interpolate the file for you at the correct resolution.

David, thanks for your help. I may call them soon for details.