Fibrin is an insoluble protein involved in blood clotting. It is deposited around the wound in the form of a mesh, when an injury occurs. It becomes dry and hard which leads to stop bleeding. Fibrin is developed in the blood from a soluble protein, fibrinogen.The conversion of fibrinogen to fibrin is the final stage in blood clotting. Platelets, a type of cell found in blood, release the enzyme thrombin when they come into contact with damaged tissue, and the formation of fibrin then occurs.t is deposited around the wound in the form of a mesh, when an injury occurs. It becomes dry and hard which leads to stop bleeding. Fibrin is developed in the blood from a soluble protein, fibrinogen. The conversion of fibrinogen to fibrin is the final stage in blood clotting.