Because using twisted extracts result in a cost of 100coins for each rune crafted, it is not recommended to use extracts as a means of making money; rather, it is intended for ironman players who plan to use the runes for themselves.
When using twisted extracts to craft combination runes without the use of a Binding necklace, extracts will only be consumed for successfully created runes. In other words, a rune that fails to combine will not also delete a twisted extract.
If players happen to make too many extracts, they can be refunded for 90% of their original cost by taking them to Hagus in the Scar.
Sunfire runes require an additional twisted extract for each base multiplied rune crafted. For example, if a player can craft 3 Sunfire runes per essence at 98 runecrafting, 3 twisted extract are needed per essence. Each rune created will receive the bonus multiplier provided by the extract. For the previous example, 183 Sunfire runes will be created per essence.