On March 7, 2018, two friends, Marianna Hewitt and Lauren Ireland, launched a skincare brand with exactly one product. People in the industry had told them a moisturizing mask was not exciting enough to launch a whole company. They did it anyway, in a sky-blue aluminum tube, and Summer Fridays' Jet Lag Mask sold out and became one of Sephora's bestsellers within two weeks. For a while you could barely open Instagram without seeing that tube.

What I like about that story is that Jet Lag is not a dramatic product. It is a rich, hydrating cream you leave on, and it caught on because it does something everyone needs. That is how I think about a face mask in general. I reach for one for one of two reasons: my skin feels tight and dry, or it feels congested. The masks for each could not be more different, and using the wrong one is how you end up irritated.

So this edit is split in two. The first grid is hydrating and overnight masks, the ones you can sleep in or leave on like a thick night cream. The second is clay and exfoliating masks, for oil, pores and dullness, which you rinse off and use sparingly.

Here is a test I like: press a clean tissue to your face an hour after washing. If it comes away with oil, start with the second grid. If your skin feels tight and the tissue is clean, start with the first.

These are the hydrating masks for heating season, long flights and any week your skin feels tight. Several of them you can sleep in, which is the easiest habit in skincare: put it on as the last step at night, like a thick night cream, and wake up to softer skin.

Jet Lag is the one to start with. It works as a mask or a daily moisturizer, with niacinamide, glycerin, hyaluronic acid and ceramides, and it is the one I pack for flights. Origins Drink Up is a sleeping mask with avocado and hyaluronic acid that the brand says hydrates for 72 hours, and it is rich enough to use on dry hands too. Clinique's Moisture Surge Overnight is creamy but oil-free, a good choice for skin that does not like heavy creams. Belif's Aqua Bomb has a bouncy, jelly-pudding texture for dry, tired skin, and it feels wonderful on a warm night.

Farmacy makes two. The 10% Niacinamide Night Mask is a leave-on mask clinically tested to smooth texture, refine the look of pores and support the moisture barrier. Honey Potion Plus is a warming honey mask with ceramides and cica, lovely when your skin feels stressed.

The last two are the special-occasion ones. Augustinus Bader's The Face Cream Mask is rich but nearly invisible on skin, rinses clean and comes with a metal spatula that cools and depuffs as you apply. Dr. Barbara Sturm's Face Mask is calming, with purslane, aloe and chamomile, good when skin feels irritated.

What I would skip: a thick overnight mask on skin that is breaking out. Go lighter, or use the oil-free Clinique.

These are the rinse-off masks, and they need a lighter hand. Clay pulls oil out of pores and acids dissolve dull surface skin, which is wonderful once a week, twice at most, and far too much every night.

Clay and charcoal first. Origins Clear Improvement uses bamboo charcoal and white China clay to deep clean pores, and the brand suggests it once or twice a week. Kiehl's Rare Earth is a clay mask for clogged pores and excess oil that is made to feel comfortable while it works. Benefit's POREfessional Deep Retreat is a creamy kaolin clay that feels gentle on skin. Caudalie's Instant Detox pairs pink clay with grape and caffeine and works in about ten minutes. The Ordinary's Salicylic Acid 2% Masque adds charcoal and clay, made for skin prone to blemishes.

Then the exfoliating masks, which are for dullness rather than oil. Peter Thomas Roth's Pumpkin Enzyme Mask exfoliates with pumpkin enzymes, AHA and fine crystals, and leaves skin looking polished. OLEHENRIKSEN's Dewtopia is a five-minute flash facial with 25 percent AHAs and PHAs and a little salicylic acid.

Borghese's Fango mud mask is the old-school one, a mineral mud based on a traditional Tuscan spa treatment. Leave it on for two to five minutes and rinse before it dries, a good habit with any clay mask.

Here is a routine I like: clay on a Sunday night, then a hydrating mask from the first grid midweek.

What I would skip: an exfoliating mask the night before something important. If your skin goes pink, it needs a day to settle.

I think a face mask is the most enjoyable fifteen minutes in skincare, and the most misunderstood. A mask is not a miracle. It is a concentrated dose of one thing, moisture or exfoliation, and the trick is giving your skin the one it is asking for.

My rhythm is simple: clay or acid once a week, hydrating once or twice, and an overnight mask whenever the heating comes on or I get off a plane. Start with one from each grid and adjust from there. Your skin will tell you quickly if you overdo it.