Vard gum

A soft, tacky substance, vard gum is the product of a tree which is only found in Cathrys, the second layer of Carceri. This substance can be found for sale in most major marketplaces, however, as it is especially useful for crafting earplugs, apparently being especially sound-dampening. Many planewalkers purchase a good quantity of this substance before departing for Pandemonium, as it allows one to travel there without succumbing to the maddening effects of that plane.

References

• The Planewalker's Handbook, pg. 24