This is a great model. However, for 3d printing the under chin portion needs to be bolstered. It breaks easily whether printed in PLA or PETG, it is simply too thin about 3 to 12 mm from the attachment to the main chin portion. I took the model into mesh mixer and thickened the areas up to the curve and that resolves the issue. However a nice rib along that lower portion up to the curve would make this model truly awesome.