BeginnerEnchanting & brewing
Potion brewing in Minecraft: every recipe in one place
Tested 26.3

A Cobweb is a sticky web that slows almost everything that moves through it.
It cannot be crafted; it can be found in chests.
Cobwebs fill mineshafts and appear around spiders' spots. A sword cuts them fast and drops String; shears or Silk Touch keep the web itself. They also slow falls and projectiles, and the Weaving effect leaves new cobwebs where its bearer dies.
This item has no crafting recipe.
Broken with Shears or a Silk Touch tool, the block drops itself; otherwise it drops String. It can be found as loot in Abandoned Camp.
It slows movement and is a source of string. Brewing: it turns potions into Mundane Potion and Potion of Weaving.
No: when a piston pushes it, it breaks and drops as an item.