Talk:Sting
From Tolkien Gateway
I added a note that Sting glows in the vicinity of giant spiders. In the Hobbit, the spiders were able to track Bilbo while he wore the Ring, because they could still see the light shed by Sting. Sting also glowed when Bilbo and Sam faced Shelob in her cave, and when Sam later fought Shelob in the pass.
Sting also cut through Shelob's webs and the webs of the spiders of Mirkwood without difficulty, while Sam's blade from the Barrow Downs (made in Arnor for use against Angmar) wouldn't cut Shelob's webs.