Soviet Union ink bottle - device and principle of operation. 

Soviet Union ink bottle - device and principle of operation.
I think the principle of the “shedding” will become clear to you after watching this video.
The whole secret is that the top of the entrance to this inkwell is arranged in the form of an overturned conical funnel, which prevents the ink from pouring out when capsizing.
Thanks to this design, which prevents the ink from leaking out when tilting or turning over, the non-spill ink bottle allows carrying ready-to-use ink with you, which was a very important circumstance until the invention of refillable piston pens.
It was believed that the famous shedding was a Soviet invention, but the first, so-called “safe” inkwells were invented by English glassblowers around the 17th century. Making glass vessels for ink, they began to bend the edges of the bottle inside - when tipping over, the ink fell into the depth of the bend and did not pour out.
Soviet shedding was made on the same principle and they were made of glass, faience and even a special carbolite material. Used everywhere in schools and in public institutions and in everyday life.
Today, according to this principle, children's plastic spills are made from plastic for working with brushes and paints. But fans also have freshly made ceramic inkwells. They are made piece by piece and are not at all cheap.
My inkwell was purchased by me for a reasonable price at a flea market in the glorious city of Chernigov, in fraternal Ukraine. And if you want to buy this rarity, look at the ads on the network, for sure someone nearby is selling a spill that has been preserved from grandmothers and you will also be able to experience this miracle in business.