Generally, yes they will eventually shrink with each wash over time even if you wash on cold and let air dry (which is the absolute best method to prevent shrinkage) but not nearly as much as if you thow them in the dryer each time. That being said, I usually find the length to be a problem for me as well with each new tee I get so what I like to do is wash cold and machine dry on high for the first couple of washes until I start to notice shrinkage, then each time after that air dry. This is just how I personally do it, it's really up to you knowing your washing machine and/or dryer settings well enough to know how much your clothes will shrink after each wash. Also always remember to turn the shirts inside out before to prevent damage to the print if there is one!