A sheet mask and a hydrogel mask look the same at first glance: a ready-made shape you place on the face, leave for a while and take off. These are the two formats of Korean face masks most often confused with each other, and the difference is the carrier. A sheet mask is a thin cloth soaked in essence. A hydrogel has no cloth at all: the gel itself is the essence in solid form, and it clings to the skin across its whole surface.
The real trap when choosing is wear time, because with hydrogels it is not standard. One mask is meant to come off after fifteen to twenty minutes; another is built to stay on for hours, even overnight — and both are right, they are simply designed differently. So the line on the packaging that says how long to wear it is worth reading before you buy, not after.
Sheet masks are more predictable: ten to fifteen minutes, then the remaining essence is gently massaged in — no rinsing needed. For a daily routine there are jars of thirty sheets, designed so you pull out one a day; a single sachet suits an occasional treatment or a first try.
If you are torn between two masks, compare two things: how long the mask stays on the skin and what the essence is meant to do — hydrate, calm or firm. The format is a matter of habit; the wear time is a matter of the directions.
