Feather.

A day round the house so I took the opportunity to have a play with various items around the house.  Trying to get a blip.  Of the things I tried this feather appealed most.

I think it was probably because unlike most feathers the bards on the vane don't interlock.   I am fairly sure this is an Ostrich feather so that would account for it.  Ostriches are flightless birds and so don't need the feathers stiffened to prevent air getting throught.

Most unusually for me I have done this as monochrome, although you would hardly notice.