There is a popular saying when it comes to preferences in pieces of clothing that many have come to subscribe to, and it states that in concerns of clothing or wearable's, it should be comfort before fashion, since if a person feels good about what they wear, then it will look good on them.
This adage would do well to apply to , since the entire purpose of advertising on shirts is for the people to wear them, and wear them often, and wear them to places where other people would also see them wearing it, thus producing an implied endorsement.
With this in mind, it is therefore an essential that the be, at the very least, unquestionable comfortable, and if possible, of a fashion or style that will make it timeless, so that it can be worn regardless of the occasion or venue, along with other accoutrements.
While it is understood that should be of a price that is affordable to be printed out in bulk, the material and comfort it produces consumer should not be sacrificed, since wearing it is the entire purpose of the exercise.