When Maddy Borch complained to her older sister about her makeup peeling off prematurely during Shabbat, her sister was ready with an unusual beauty tip: “Spray hairspray all over your face, to set the makeup.”

Instead of laughing it off, Borch complied.

And now?

“I’ve been doing it for the past year — it really works. My makeup can stay on for three days!” says the 24-year-old special-education teacher from Flatbush, who buys high-end Kenra spray on eBay for $25. “I spray each eye once, and cheeks once. If I use a cheaper one, like White Rain, the makeup doesn’t stay on as well.”

Many women are known to go to great lengths for their beauty regimen, but beauty junkies in the Orthodox faith have an additional hurdle: Religious law forbids any kind of work — this includes retouching makeup or styling hair — for 24 to 48 hours on Jewish holidays and from sundown Friday to sundown Saturday.

As a result, many Orthodox women employ beauty secrets that can be shocking — from using a non-cosmetic Sharpie pen as eyeliner to slurping soup through a straw so lipstick remains undisturbed.

Long-lasting cosmetics are also prized, but their results aren’t always as advertised. Earlier this month, an upstate Orthodox woman sued makeup giant Lancôme on the grounds that its Teint Idole Ultra 24H foundation, which promises “24-hour wear for divine, lasting perfection,” “faded significantly” overnight.

While the lawsuit seemed a little “extreme and over-the-top” to Sharon Langert, the busy mom of five can also relate.

“I can’t judge her. If someone has bad skin and they depend on [the product] and it doesn’t last, then it affects their self-esteem,” says Langert, 44, who is Orthodox and the founder of fashion-isha.com, a style site for the modest Jewish woman.

A cosmetics hound who buys her MAC liquid eyeliner two at a time, Langert refuses to leave the house without makeup — as do many of her friends — and she knows first-hand the struggles caused by Shabbat.

“I know some women who sip their soup with a straw, so it won’t ruin their makeup,” says Langert. “Some women tell their husbands not to touch them on Friday night!”

Mimi Hecht, 27, a kosher style blogger at Ladymama.org from Crown Heights, admits that she once resorted to using a non-cosmetic Sharpie as eyeliner to get her through a two-day holiday.

“I’ve done it once, and then couldn’t bring myself to do it again,” she confesses. “But it did the trick!”

The married mom of two says she’s long battled “the challenge of not being able to apply makeup for Shabbat and extended holidays.”

“When I was single, I would literally use like a whole pound of gel and mousse in my hair to make it last for Shabbat,” recalls Hecht. “But you’ve got to do what you’ve got to do.”

Hecht’s hair woes have nothing on Ruti Horn, who recalls one, um, unorthodox beauty trick passed onto her from her mother.

“When I was little, my mother would tell me to sleep with my hair in a sock, so that it stays and I wouldn’t have to worry about touching it up with an iron the next day,” says the 20-year old accessories designer from Midwood.

Many Orthodox women say one of their biggest challenges is achieving lipstick that lasts.

“I would layer on some crazy [long-lasting] Max Factor Lipfinity lipstick and not eat anything with oil that can take it off,” says A.J. Gross, 27, of Elizabeth, NJ.

And then there are those who go heavy on the makeup offensive: “Apply ‘drag queen’ foundation before Shabbat. That stuff doesn’t move!” swears Estee Gottlieb, 23, from Crown Heights. “Sleep on your back, and you’re good to go! I wear MAC; it’s heavy, like paint, and it stays on all day!”

According to Orthodox beauty experts, the key to long-lasting makeup — minus the clown face — is to layer. Kosher cosmetologist Elana Barkats, 27, of the Upper East Side, recommends using a primer, followed by foundation and powder to set.

She also dabs foundation on her lips before applying lipstick, to help it stay in place. And she recommends avoiding the sun, which will melt the makeup off any woman’s face.

She says women outside the faith could learn a thing or two from her advice.

“I think our knowledge would benefit a lot of people; they want to do it and be done with it, and not have to reapply,” says Barkats.

But even Orthodox women who go to extreme lengths for their beauty regime try to maintain perspective.

Says Langert: “I personally love makeup, but if you’re an Orthodox woman in an Orthodox community, you kind of accept that on Saturday, you won’t look the same as during the week.”

dlewak@nypost.com