Gossamer is a light armor set. When you heal a friendly target, you have a 10% chance to grant them Major Evasion for 6 seconds, increasing their area of effect damage reduction by 25%.
The Gossamer set is part of the Shadows of the Hist DLC. It drops in Cradle of Shadows in Shadowfen. Each set item is bound on pickup. You can acquire light armor, weapons and jewelry of this set in the Silken Ring motif style.