GNick55, I am very new to this, I do have cheap screens and produced a little dust when I worked some product year before last. Medical issues stopped me this last year, but I am going to (again) play with my screens this winter season.
I was wondering why you use your screens with the lips facing down? I was using my screens with the lips up (like you use your first screen), and have risers on holding up the bottom screen from the table top.
Just seems that things falling through the layers would have the edges of the screen to hold it in and not have an edge that you would need to be careful of not carding over when working the material.