Sure Shirts are made of a very comfortable thin wrinkle fabric that looks best with lots of little crinkles (and not ironed!). The fabric is 100% cotton and fit for washing machine. With the crinkles, this fabric is very strechable, which makes correct sizing a bit difficult. In fact these shirt’s sizes do differ from motif to motif and even color to color.
If you prefer the fabric uncreased and smooth, do as you please (they will certainly turn out a bit bigger then). If you like the wrinkle / crinkle look, just twist the shirts length-side, instead of folding them, before you put them in your wardrobe.
A second layer of “tattered” fabric is sewn onto the neck’s and the sleeve’s ends. That little feature gives the shirt a cool worn out or rampage appearance. In fact though it even gives more support and prevents fraying.