How to work with metallics without tearing the fabric? Very carefully!
Blending filament is easier as its diameter is so thin.
For all metallics, I recommend using Thread Heaven, which coats the thread without stickyness. You use only a bit, so it lasts quite a while.
The thicker metallics need to be used in short lengths, like 8-9 inches.
I highly recommend reading the internet page kreinik.com
They make metallic floss and have more info about it.