Shumai wrappers tend to be smaller and thinner than wonton and gyoza wrappers, but they should work. The wrappers I used were 2.75-inches square (7cm). If you use larger wrappers, you'll need to add more filling to each dumpling (so the recipe will make less Shumai), and you'll also need to increase the steaming time to ensure they are cooked through. I recommend avoiding thicker potsticker wrappers that are any thicker than a credit card.