My resident fabric expert tells me that the grills on my Original Advents are made of Rayon and are definitely not linen. Take a short piece of thread and burn it , then smell the smoke and it is obvious. This is why it frays so readily and the weave distorts so easily. This is a standard test for linen, silk, wool, cotton vs synthetics. I am looking for a source as well. Lets try looking for Rayon.