We've tried a few different ones and I've let bulletpaluza test them out since he's pretty tough on shirts. We haven't gone with a particular brand yet but thanks for the feedback. Will definitely consider this information when we look to buy shirts in bulk.
Your printing looks good. I'll think on something I'd like. I prefer subtle that only people here and others like us would get leaving the sheep confused. Actually, that would be kind of cool. A great pyrenees or irish wolfhound in front of a sheep with a wolf in its mouth. Wish I was an artist. Maybe someone on here with talent could draw it out for you.