Oakum
Oakum can be used to seal cast iron pipe drains. After setting the pipes together, workers pack oakum into the joints, then pour molten lead into the joint to create a permanent seal. The oakum swells and seals the joint, the "tar" in the oakum prevents rot, and the lead keeps the joint physically tight.
Today, modern methods, such as rubber seals (for example, gaskets or o-rings) are more common.
Tuilik
The tuilik must seal reasonably at the face and kayak cockpit coaming, and usually at the wrists. This is done using smooth, stretchy, grippy materials. Both laminate fabrics and neoprene will seal, but stretchier neoprene often seals better, so some non-neoprene tuiliks have neoprene rands. Stretchier neoprene with one smooth side may grip and seal better, so even neoprene tuilikusaqs may use a different neoprene for the seals.