Discuss the wholesale blanks industry: Factory direct, custom labels. You can also use this forum to locate a wide variety of wholesale products including t-shirts, hoodies, mousepads, coffee mugs and other imprintable products.
I have no clue what these shirts are called, but you're starting to see a lot of them in sporting goods stores. I've seen them listed as "base layers" in some hunting departments and in skiing outfitters.
These shirts are very lightweight and thin; and most, if not all, have been long-sleeve. They also claim to dissipate moisture rapidly.
These are different from golf shirts and much much thinner. The fabric is not so thin that you can see through it, though..
I purchased a shirt similar and it is printed on. The print is very very soft and it's hard to feel anything at all. For sure it's not vinyl and if it is screen print it's like nothing I've seen. There is no "bump" on the graphic where the graphic meets the shirt. Everything is smooth and nice feeling. Maybe some sort of ink transfer? I have the ability to do ink transfers, but I have not had the demand to do any so I'm unfamiliar with this type of transfer.
I print on solutions opaque, from Imprintables Warehouse, and heat apply. It leaves a very soft hand and the edge feels as if it is part of the material. I print my own on a Versacamm but you can purchase digital prints through Stahls and Transfer Express.
Solutions opaque is a printable heat applied film using eco-sovent inks. For those who don't have an eco-solvent printer/cutter you can order the prints from Stahls or Transfer Express.
Thin, lightweight, base layer type blanks 
