It tightens and stiffens fabric stretched over airframes, which renders them airtight and weatherproof. The heated material flows more easily in tension, but cools and stiffens under compression. As the leather dries it stiffens and holds its shape. She stiffens and fearfully opens her eyes to see Miriam staring at her. The body stiffens for about a minute and then jerks uncontrollably for the next minute. Refrigeration also stiffens the dough, which still rises, albeit slowly, making it easier to form. In restrictive cardiomyopathy the ventricle stiffens. The protein keratin stiffens epidermal tissue to form fingernails. This tape reduces canopy oscillations and stiffens the wing in flight. This mineralization of the collagen matrix stiffens it and transforms it into bone. A shear pin on the machine prevents damage as the testing material stiffens. Heesy shows that the postorbital bar stiffens the lateral orbit. The size stiffens the thread and helps the fibres lie closely together. At that point she stiffens as 6,600-volts AC is applied to her body. The banks do not overflow and the lice choke as the arm stiffens.