A slab is a slang expression for cannabis used to describe a huge portion of concentrate.
Generally, it is made by spreading the concentrate to a thin layer on a baking sheet and to heat it slowly till it melts. Once melted, it is then cooled to room temperature. While creating a slab, the concentrate is placed on a piece of baking paper to heat it slowly till it melts, then the product is cooled to room temperature. With the thin layer you can see the clarity, colors, purity, and density of the product. It is then divided into small parts for use in a dab rig.
Usage: “Take out the slab; I want to do a lot of dabs!”