Rubber mache

Body is foam colored with a marking pen, wrapped in spawn sack, dimpled with thread and soaked in Stretchable Flexible fabric cement. Water doesn't bother it but heat does, unfortunately. So you have to keep flies like this in an opaque plastic box rather than a clear one. Else they get too hot if left out in the July sun. And they start to get sticky. Otherwise it's a good way to mark up the foam.