With a boom in face masks in the last few seasons, that old-time ritual of putting on a face mask in the privacy of one’s home is seriously passé. “Masking” is well out in the open.

In fact, there is even a beauty phenomenon called mask bingeing. “That’s when people put on several different masks in a row to treat whatever they want,” said Lev Glazman, a founder of the Fresh skin-care line.

Mr. Glazman credits millennials on Instagram for the proliferation of face mask products. “Millennials are triggering something in beauty, and then the other groups are looking and maybe following,” he said, adding that he has learned a lot from his daughters, ages 18 and 22.

“When you look at what millennials love, they like to see something that happens quickly,” he said. “That’s what you can get with a mask: the instant effect.”

Immediate gratification is certainly part of the appeal, but so is the visual shock value. (Hello? More followers.) Popular Instagram hashtags like #facemask and #multimasking showcase applications that resemble tribal art or odes to horror movies.

Such popularity has spawned a truly diverse range of offerings: sheet masks, mud masks, overnight masks, bubbling masks, splash masks and more. Below, we’ve done the legwork (facework?) and put together a facial mask primer.

Splash Masks

The newest on the block, splash masks, originated in Korea and are meant to play nicely with your in-shower lineup. Simply do your usual regimen, then splash on the mask and rinse off. On a trial run, the Blithe Soothing and Healing Green Tea Splash Mask ($45 at Sephora) offered a refreshing quality and, surprisingly, an exfoliating effect courtesy of its concentrated lactic acid content.

Even so, Neil Sadick, a dermatologist in Manhattan, is skeptical. “The point of a mask is that it improves target delivery because it’s sitting on your skin,” he said. “This delivery system is more a cleanser than a mask.”

Bubbling Masks

These are novel for their texture — they actually froth — and claim oxygenating benefits. Some very bubbly formulas may even tickle when under your nose. While the effervescent Dr. Brandt Oxygen Flash Facial Recovery Mask ($70 at Dr. Brandt Skincare) won’t replace your morning run, it produces a noticeable brightening effect.

Sheet Masks

When even Justin Bieber posts on Instagram about his sheet mask experience (he used the Talika Bio Enzyme Hydrating Mask), this is a beauty trend that has gone pop. The gist? Slap on an individually packaged, serum-soaked sheet mask (often made of cellulose or cotton, but also offered in gel form), frighten your significant other with Freddy Krueger scary faces and come away with a more glowing countenance. (Most sheet masks are of the hydrating variety.)

Though the SK-II classic sheet mask is still a beauty editor favorite, more-daring souls will want to try the Tony Moly Intense Care Snail Hydro Gel Mask ($8 at Ulta). It contains snail secretions (yes, it feels a little slimy) and offers nice skin softening and balancing benefits.

Mud and Clay Masks

If a splash mask is Snapchat, a mud mask is Facebook. The category has been around but keeps mixing things up with eye-catching new features. One recent arrival, GlamGlow’s GravityMud Firming Treatment ($69 at GlamGlow), boasts glacial clay to sop up oil and boost tone. The nifty part? The mask turns from white to chrome (tailor-made for Instagram, or what?) after application.

Hydrating Masks

Often found as creams but also more recently in gel form like the pretty translucent pink of the Peter Thomas Roth Rose Stem Cell Bio-Repair Mask ($52 at Peter Thomas Roth), hydrating masks are generally straightforward: They offer a boost of moisture for parched skin.

Exfoliating Masks

Though the idea of sloughing away sun damage sounds enticing, Dr. Sadick suggests a more cautious approach to exfoliation. “Masks can be concentrated, and if you’re using a mask with a strong ingredient like glycolic acid, make sure you know what the concentration is,” he said. “Otherwise, something with a vitamin C base might be a little safer to use.” Fresh’s newest offering, the Vitamin Nectar Vibrancy-Boosting Face Mask ($62 at Fresh), certainly qualifies. The gel-paste is so citrus-heavy (a blend of oranges, lemons and clementines) you’ll actually feel the pulp when slathering it on.

Sleeping Masks

If moisture is what you’re after, it’s usually best to leave the mask on longer. That’s where sleeping masks, which profess to revitalize complexions while you snooze, come in. The Dior Hydra Life Jelly Sleeping Mask, particularly, produced admirable skin-plumping ($69 at Dior). (Be wary of leaving on harsher active ingredients, like alpha hydroxy acids, for too long, Dr. Sadick said as a caution.)

Tanning Masks

If you’re willing to put your pillowcases to the test, these overnight self-tanning formulas, like the James Read Sleep Mask Tan Face ($38 at Sephora), promise gradual (ergo, believable) results without staining bed linens.

Mask Primers

When just one product won’t do, Origins offers a new mask primer, with the name Maskimizer ($22 at Origins). The spray claims to prep skin for mask treatments, though we can’t say for certain that a long hot shower wouldn’t do just as well.