to starched linen, first in the water, add the starch and mix. The starch in the water not rastvorjaetsja, and floats it in the form of mist. It is then soaked underwear to be starched. When soaking starch penetrates into the fabric structure, impregnates her. And then the linen press and put under the iron. When linen is ironed with a hot iron, starch from the intense heat turns into dextrin.
On linen produces a hard crust, like the one on the potatoes.
Therefore, starched collars such firm that the neck cut.