When are you going to start carrying bigger sizes? K
Maybe suggest the sizes you are looking for.
Also @Froodyfrog.
That’s an awesome idea, 5X and 6X would be great, then I could gift them to my brother in law and his son! I buy the biggest size available (3X) for myself and wear them for nightshirts. 
I’d love 4X for myself, as the 3X is a bit of a stretch on me. But to keep the prices down and still pay the artists something, they had to use a shirt maker that not only produces a lighter weight shirt than the major brands you might see in the shops, they do not go any larger than the 3X. I don’t generally wear these outside the house (though that does kind of defeat the concept of shirts with a message) because since they also are not “talls” they tend to drift up above my belt line all the time. As I’m well over the 6 foot mark, no shirt that is not a tall fails to look like I’m wearing some childs clothing. But you get used to it after a while.
Would it be possible to offer the larger sizes and up their price by a $1 or $2? This way Wooters can get larger sizes but pay a little more.
Now do dogs.