Are this shirts "relaxed fit" as opposed to other shirts out there that are "slim fit"? for a ccw shirt i want to know if printing would be an issue.

Not being a fashion guru, I agree with the others regarding the 'relaxed fit' style. As for whether this shirt will or can result in 'CCW Printing' depends on a few other things like body type, shirt size, overall fit, size of weapon, holster, etc. All these considerations will determine if or how much 'CCW printing' will present itself.Being 6 ft. & 190 lb, I get away with small (.380) to medium size semi (9mm) inside the waistband or body hugging holster , but I wouldn't jump or run around and expect the weapon to remain concealed. I suggest if wanted to use this shirt as CCW clothing the best assessment would be for you to determine if this shirt and firearm are a good fit by trying it on. Be sure to practice drawing any weapon with this shirt on to see if this meets your personal CCW requirements. But, it's a good comfortable shirt, CCW or not...

Snaps or buttons? Thanks.

snap buttons - they are woven in to the shirt.

Is there a size chart or comparison

Runs true to size. I usually order XL in most button ups for CC so I don't print. I'm 6' 220 athletic build. I have XL and L sizes of this shirt in SS and LS. I wear a tee under the XL and carry 4 o'clock. I wear L for modern fashion look, fits well just have to carry appendix. Shirt has a lot of flex in 4 directions and breathes really well. If your borderline XL-L. I'd go L unless you like a lot of room. Awesome shirt. I have 4

Do these shirts have a vent in the back?

Shirt does not have a vent like some of the Nike PFG shirts. It does have perforations on the sleeves abs all the way across the upper shoulder/back portion. I really like the shirt and it breathes well.