Depends on which mask you’re using.
There are different kinds of blackheads removal mask – Charcoal mask, Clay mask, Salicylic acid, Calcium Bentonite Clay, Lactic Acid, Glycolic Acid Mask and many others. The right one for your skin depends on the severity of blackhead and your skin type.
Usually, blackheads removal mask works by unclogging pores, absorbing excess oils, detoxifying, exfoliating dead skin cells to leave behind clean dirt-free skin.
Note: Overusing blackheads removal masks will lead to irritation and redness.