Cementing Paste is used in a great many crafting projects in Ark. In fact you'll probably need a good quantity of this stuff. The question is how do you efficiently make the amounts you need? The materials can be harvested by hand, but you can also harvest insects with a Beezlebufo, which sometimes converts killed insects directly into cementing paste.
Cementing Paste is made in the Mortar and Pestle or by the Beezlebufo when it eats insects. To make it in the Mortar and Pestle you'll need 4 Chitin (or Keratin) and 8 Stone.
So far in my experiments, I've found that harvesting with the Beezlebufo is quite slow unless you go into the deep swamp where there are a lot of insects. Although, considering the time which that takes, it's actually still quite slow.
The fastest way I have found to create cementing paste is through hunting Trilobites for Chitin (you can also get Oil and Silica Pearls this way). Then use a Doedicurus to mass harvest stone. Toss it all in the Mortar and Pestle, and craft away.