I hear that questions often.  Several components go into the answer.  Aside from the previous discussion about decoration, the key factor is the quality desired in the shirt.  Here are the basic options and there are many variations:

    Jersey Knit is basically heavy weight tee shirt material. Both Hanes and Jerzees have styles.  I use it often with school uniform and apartment maintenance apparel programs.  There is nothing wrong with the shirts but you will definitely feel a difference in weight.

    Pique has been a standard for many applications.  The classic collared shirt like the Outer Banks 2100 (men’s/unisex) and 2400 (ladies) is a pique.  Courser knit than the jersey, it has a higher perceived value than jersey.  Where the jersey kit is 5.5 oz material, pique will be 6.5 oz. and 7.0.  Good apparel catalogues will tell you this measure of quality.

    Pima Cotton has become very popular in the last few years.  Many of my clients who were pique shirt buyers have now switched to pima cotton which uses a longer strand of cotton and has a smoother feel (technical term is “hand”).  Pima will run about $2-3.00 more but people are telling me the difference is worth it, especially when the shirts are being sold and not given away.  On the companycasuals site listed below, look for the K448 and L448.
    Interlock is a method of weaving in which the surface is smooth on each side.  Haven’t sold one in years.  New fabrics are out that feature ability to pull moisture away from the body.  That process is nice for someone out of doors in the summer like a golfer.