Quality control of down-feather materials starts with visual analysis.
It should be done in daylight on a dark table surface. Place 100-150 g of material, palpate it with hands and flip up small amount of it.
Visually determine the presence of the following indicators: its softness, the ratio of white and gray feathers and down, the presence of lumps, nap, the presence of used material (i.e. down feathers, moth-eaten feathers and flocks, broken parts). The number of feathers, the presence of a peeled feather, the presence or absence of a chicken feather, etc.
The raw materials are then weighed, dried and examined through a microscope.