Updated as of latest patch on 09/08/2021Fiber
in New World is obtained by harvesting Hemp plants
in the forest regions of Aeternum. They are purple topped plants that are located within the forest and grassland areas.
You can press M, bring up your map and click on the Resource locations icon to see what regions of the map certain resources are located.
To harvest the hemp you just walk up to it and press the default harvest key of "E". Once the harvesting is complete you’ll get fiber from the plant.
You can also check out our interactive map
for a ton of resource locations.