Cotton Lawn fabric is a plain weave material made from fine combed cotton threads. Because it is woven very closely it creates a smooth, even surface on the fabric. It drapes nicely and is a lightweight, breathable dress fabric.
Generally speaking, Cotton Voile is fairly similar to Cotton Lawn but is lighter in weight and sheerer.
Poplin is a durable, lightweight cotton, thicker than cotton lawn. It’s not dissimilar to quilting cotton, though of a lighter heft and less prone to creasing.