I have the Leopard Head print shirt which is very lightweight but not poplin. Some retailers online dont mention the weight and some do. Its best to see them in person if possible.
Tried the Banana print shortsleeve on the other day which is part of the S/S collection and the fabric was heavy which was surprising Nice shirt though
Is there one you have been in mind.
The "luck one" is light. If you have a particular one I live a few blocks away from a few stores that carry them I can take a look for you before you order