Matte Photo Printing Service

Does anyone know of a photo printing service that we could integrate with for printing photos in matte? Both ShutterFly and PhotoWorks don't allow you to select matte as an option in the Gallery linked cart. However they both do support printing matte for photos in their own cart. I emailed PhotoWorks and asked them about this. They said they had no plans to add the matte option to the Gallery cart. This is really a bummer since I get most of my photo's printed in matte. Any ideas?

Thanks.

-James