Guild Wars 2

What are all possible ways for thiefs to grant area stealth to allies?

Also, Shadow’s Embrace: Remove conditions periodically while in steath, does this affect the allies granted stealth by us?

Shadow Refuge
Black Powder / Smoke Screen + Blast Finisher (Cluster Bomb or Blinding Powder)
Blinding Powder
Last Refuge Trait

And the only Stealth related traits that affect allies are Shadow Protector (Regen on Stealth) and Resilience of Shadows (25% Reduced Damage).

Use Blast Finishers on any Smoke combo field.