I get silk in ragnarok from the purple flowers and I harvest them with a metal sickle or therizino
Gachas produce these.
About 60 Silk per good crystal.
Spiders do not drop this. It can be harvested from the purple flowers in the highlands on rag or from killing lymantria
Have you seen those weird looking butterflies? Kill them and harvest them using a chainsaw. You will have enough to make lots of fancy stuff for you and your tribe
On Scorched earth, Silk can be found on on small bushes that are low to the ground.
Megachelon through the genesis ocean floor will solve all of your silk needs (beware of server lag)
Use a sickle on the white flowers on SE to get lots of silk and fiber.
I once got serveral hundred silk off one of the farting moths and I only used a metal hatchet.
Good stuff, makes whips to get your enemies off of pesky games.