How Do Make-Up Setting Sprays Work? (With Video)

Makeup Setting Spray Science

If you don’t already use a make-up setting spray in your make-up routine, you’re missing out. They make your make-up look less powdery and more blended, and can act as a shield against sweat and rubbing and general clumping as well. If you’re wondering how they work, or how to find a dupe, I’ve got you covered!

Check out the video on YouTube here.

Types of Setting Sprays

There are two types of setting sprays:

  • sprays that shield against sweat, rubbing and clumping, AND make your make-up look less powdery/more blended
  • sprays that only make your make-up look less powdery and more blended (this can also help with clumping)

Confusingly, the name “setting spray” is used for both. “Fixing” is usually only used for the first type that shields.

Setting Sprays That Shield

Let’s start with the shielding and de-powdering sprays. These contain polymers dissolved in a solvent, usually alcohol. Polymers are long molecules like plastics which are great at forming films that don’t budge.

When the setting spray is sprayed onto your skin, the solvent evaporates, leaving behind the polymer. The polymer droplets merge together to form a film that holds your make-up in place and provides some waterproofing power.

The solvent also acts to dissolve your make-up slightly and help it merge together so it looks more blended. Unfortunately, if you spray too much, the solvent will dissolve your make-up and make it run, so make sure you use a fine spray (test new sprays on your hand before you ruin your face!).

These types of sprays will generally have a polymer in the first 4 ingredients. The most common polymers found in setting sprays are PVP (polyvinylpyrrolidone) and AMP-acrylates copolymers.

If you’re looking for a dupe of a setting spray that works well for you, a good place to start are different setting sprays with the same polymer. While the other ingredients in the formulation will also make a difference (for example, the dewy and matte NYX setting sprays contain the same polymer, and some sprays like Algenist Splash Hydrating Setting Mist contain beneficial skincare ingredients), the polymer is crucial to how well it performs.

A lot of the same polymers are used as the holding ingredients in hairspray, so hairspray can work as a make-up setting spray in a pinch!

How Do Make-Up Setting Sprays Work?

Examples of settings sprays that shield, sorted by polymer and listed in alphabetical order:

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Silicone Mythbusting (with Video)

Silicone Mythbusting Video

This post is sponsored by Grant Industries. Silicones are one of the Big Bad ingredients in skincare, make-up and haircare. They’ve been demonised by natural brands, and there are more warnings about them than you can count. So I was delighted when Grant Industries (ingredient manufacturer, maker of Granactive Retinoid, physical sunscreens and of course, silicones) asked me to do a …

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My Travel Skincare and Makeup Bags

Skincare and Makeup Travel Bags

I travelled to France and England recently, and some people asked me what I packed – so I filmed some videos talking about the products I brought with me. Here they are! Note: You might need to disable ad-blocking to watch these. Travel Skincare Bag Ultraceuticals Daily Moisturiser SPF 30 Mattifying Real Barrier Cream Cleansing Foam Bioderma Sensibio H2O Micellar …

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Foundation Clumping Science, and How to Fix It (with Video)

Foundation Compatibility (with Video)

You might’ve had the experience where you apply your foundation over primer/moisturiser/sunscreen etc., and then a little while later your foundation’s gone clumpy. This is foundation incompatilibility. What’s happening, and what can you do to avoid it? Let’s talk about the science behind foundation! [Note: I would recommend watching the video in addition to reading the post, if you’re usually …

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How to Use Comedogenicity Ratings (with Video)


You’ve probably seen a comedogenicity chart like these ones (and the one further down the page) before, rating different ingredients on their ability to cause pimples.

Supposedly you check the ingredients list of your product against the comedogenicity list. If it has highly comedogenic ingredients, it will cause pimples, if it doesn’t, then it won’t. It’s simple, systematic and foolproof, right? Unfortunately, it’s not quite that simple…

This post goes into the science behind these comedogenicity ratings, and how exactly you should use them. It also comes in video form!

Click here for the video, scroll down for the rest of the blog post…

What does comedogenicity mean?

Comedogenicity is the tendency of an ingredient or product to clog pores. Ingredients are ranked on a scale:

  • 0 – completely non-comedogenic
  • 1 – Slightly comedogenic
  • 2-3 – Moderately comedogenic
  • 4-5 – Severely comedogenic

The numbers in comedogenicity scales come from studies performed by academics, published in peer reviewed journals – this usually means they’re somewhat reliable and valid. However, like with many other skincare claims “supported by the literature”, problems emerge when you dig deeper!

What’s wrong with the comedogenicity scale?

The problem is that the studies that produced the comedogenicity ratings don’t reflect real-world usage, for a number of reasons:

Tests aren’t done in real-world conditions

In an ideal world, we’d test every single product on every single person’s face, and develop a definitive comedogenicity rating list based on that. But this would be impossible – it would cost too much, there are too many products, and getting a lot of people to only use the one product and not change their daily routine for weeks or months at a time would be a mammoth task.

Instead, what’s used in most scientific studies is a model – a situation that mimics the real world, but is simpler to carry out and control. Think crash test dummies, dyed samples of hair, pouring blue liquid onto sanitary pads, patch testing potential allergens on your arm, testing bikes on a race track.

Most of the time these models work pretty well, but sometimes they don’t reflect the real world situation, so their results can’t be applied to everyday life (they have low external validity). In the case of comedogenicity ratings, the models don’t fare so well.

The most common rabbit ear test is flawed

The most common test for comedogenicity is the rabbit ear test, pioneered in cosmetics testing by two famous dermatologists, Albert Kligman and James Fulton, in the 1970s. This involves applying a substance to the inner ear of a rabbit, and waiting a few weeks to see if any clogged pores formed. Because rabbit ears are more sensitive than human skin, they reacted to comedogenic products faster, which was more convenient.


Unfortunately, this also meant that there were lots of false positives, where ingredients that are non-comedogenic in humans would be found to be comedogenic in the hypersensitive rabbit model. Additionally, in the original tests, the scientists didn’t realise that there are naturally enlarged pores in rabbit ears. Some results counted these as acne, leading to even more false positives.

Related post: Purging vs Breakouts: When to Ditch Your Skincare

The most famous false positive is petroleum jelly (petrolatum or Vaseline), which was corrected in the late 1980s, but this was debated until the mid-1990s – that’s why the myth that Vaseline and oily products cause pimples is still so pervasive. This wasn’t the first time the rabbit ear tests were questioned – conflicting results were commonplace, and comedogenicity lists frequently disagreed with each other (and still do).

Related post: Is Mineral Oil Dangerous?

More recently in 2007, dermatologists Mirshahpanah and Maibach went so far as to say:

“[the rabbit ear] model is unable to accurately depict the acnegenic potential of chemical compounds, and is therefore only valuable for distinguishing absolute negatives.” – Mirshahpanah and Maibach, 2007

Tests on human subjects are also flawed

If rabbit ears don’t reflect what happens on human skin, then the obvious solution is to test on humans, right? Yes…but there are problems there too!

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Skincare Favourites 2018 (Empties Video)

Skincare Favourites Video

Videos are coming thick and fast as I try to get rid of all the old ones with my old background! This time I review my favourite skincare products from 2018 that I liked enough to finish using, along with one foundation. Click here to watch the video. If you haven’t already, you can subscribe to my YouTube channel here. …

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Foundation Reviews: The Ordinary, Lancôme, Thin Lizzy

Foundation Reviews: The Ordinary, Lancôme, Thin Lizzy

Here are some reviews of foundations I’ve tried from The Ordinary, Lancome and Thin Lizzy. I actually tried them a while ago but never got around to posting about them until now! For reference, my skin is NC20 and combination oily/normal. The Ordinary Colours: Coverage and Serum Coverage and Serum are The Ordinary’s foray into make-up, and like the rest of …

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Video: Skincare and Makeup Tips for Oily Skin

Video: Skincare and Makeup Tips for Oily Skin

My skin is oily / combo and I complain about it quite a lot, so I often get asked for my best tips for controlling the inevitable flood of oil. I also sweat easily which apparently means I’m fit, but this adds to the oil and I end up a bigger mess. I’ve spent a long time trying to get the right balance of products and routines to combat the oil – here are my best skincare and make-up tips!Check out the video here – keep scrolling for the text version.

Is Your Skin Actually Oily?

Oily skin is genetic, but you can accidentally give yourself oily or oilier skin with the wrong routine. You can also have dehydrated but oily skin. Before you start doing everything to deal with oil, make sure you’re not in either situation.

(If you want details on doing a full skin assessment, you might be interested in The Lab Muffin Guide to Basic Skincare.)

Wash Your Skin Gently

Overcleansing can make oily skin worse via dehydration and irritation. There are a lot of things that go into gentle cleansing, but the two most important factors are avoiding sodium lauryl sulfate (SLS) and true soaps, and minimising your skin’s exposure to cleanser in general.

Read more about cleansingAll About Cleansing & How to Choose a Gentle Cleanser

Cleanser recommendations (not an exhaustive list):

Don’t Be Scared of Moisturiser

Oily skin can need moisturiser if it’s dehydration prone (like mine). Natural sebum doesn’t moisturise your skin that well unfortunately! For dehydrated skin, humectants and occlusives are the way to go, but if your skin is oily keep the occlusives to nighttime use.

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