Marrentill tar

Marrentill tar can be made at level 31 Herblore and yields 42.5 experience points. It is made by using marrentill with 15 swamp tars. With a pestle and mortar, 15 swamp tar, and a marrentill herb in backpack, use the herb with the tar to make marrentill tar.

These are used on orange salamanders for net trap bait. Also it is the ammo for the Orange Salamanders.

Production costs
The data in this table is based on the Grand Exchange prices of the Herb and 15xSwamp tar. It is accurate assuming all items are bought off of the Grand Exchange and the result is sold afterwards.