Ever since my eyeshadow primer comparison post, I have been inundated with requests to do a similar post focusing on foundation primers.
I did do a "drugstore dupes to the test" post comparing Smashbox Photo Finish and Monistat Anti-Chafing Gel and found that, logistically, it is much more difficult to pull off this sort of comparison for face primers. I got complaints about how people didn't trust my assessment of what happened because the pictures weren't clear enough and even some accusations that I was being paid by Smashbox to give a favorable review of their product (Obviously, this is not the case). As a result, I took pains to ensure that this comparison was as methodologically sound as I could make it (given my logistical limitations), leading to a delay in your wonderful blog-reading enjoyment.
Because I have limited bodily surface area, I had to ditch the multiple-foundation method. I still like the idea, but it was impractical. Instead, I chose one seriously intense product: Kat Von D's Lock It Foundation. Rather than using potentially smudge-y permanent marker to test for opacity, I just chose an uglier part of my skin. My forearms are looking pretty uniform in color, but my legs are blotchy and weird, meaning I have a natural test of the foundation's staying power. Finally, I chose a color that was significantly different from my natural color in order to make the foundation's effects stand out more clearly against the camera. I chose the lightest shade in the Kat Von D foundation: Light 42.
I also want to make sure that it is clear that this test only addresses one facet of foundation primer action: its ability to prolong your foundation wear-time. Things like reducing the appearance of pores are obviously not examined in this test.
(The other reason it took me so long to get to this request is because this post necessitated a trip to Sephora, and Sephora is a long-ass way away. The town I live in is too small to sell makeup... It's so small, the top story in the local paper yesterday was that Walmart's hours are changing. That sounds like a joke, but it genuinely is not.)
I compared a whopping (and numerically dissatisfying) 19 primers from 15 different brands. As before, I arranged the primers based on price per ounce, from lowest to highest.
1. Hard Candy Sheer Envy Primer, $8 for 1.6oz ($5 per ounce)
2. Laura Geller Spackle Under Makeup Primer, $36 for 4oz ($9 per ounce)
3. Bare Minerals Prime Time Foundation Primer, $23 for 1oz ($23 per ounce)
4. Pixi Beauty Flawless and Poreless Primer, $29 for 1.01oz ($28.71 per ounce)
5a. Too Faced Primed and Poreless Skin Smoothing Face Primer, $30 for 1oz ($30 per ounce)
5b. Too Faced Primed and Poreless Pure Oil-Free Skin Smoothing Face Primer, $30 for 1oz ($30 per ounce)
6. Sephora Collection Perfecting Ultra-Smoothing Primer, $15 for 0.5oz ($30 per ounce)
7a. Tarte Clean Slate Poreless 12-Hour Perfecting Primer, $30 for 1 oz ($30 per ounce)
7b. Tarte Clean Slate Flawless 12-Hour Brightening Primer, $30 for 1 oz ($30 per ounce)
8a. Urban Decay Pore Perfecting Complexion Primer Potion, $31 for 0.94 oz ($32.98 per ounce)
8b. Urban Decay Brightening & Tightening Complexion Primer Potion, $31 for 0.94 oz ($32.98 per ounce)
9. Makeup Forever HD Microperfecting Primer, $34 for 1.01 oz ($33.66 per ounce)
10. NARS Pro-Prime Pore Refining Primer, $34 for 1 oz ($34 per ounce)
11. Tarte BB Tinted Treatment 12-Hour Primer, $34 for 1 oz ($34 per ounce)
12. Paul & Joe Moisturizing Foundation Primer, $35 for 1 oz ($35 per ounce)
13. Smashbox Photo Finish Foundation Primer, $36 for 1 oz ($36 per ounce)
14. Benefit Stay Flawless 15-Hour Primer, $32 for 0.54 oz ($59.26 per ounce)
15. Mirabella Prime for Face and Eyes, $29 for 0.45 oz ($64.44 per ounce)
16. Benefit 'That Gal' Brightening Face Primer, $29 for 0.37 oz ($78.38 per ounce)
The costs ranged from $5 to $78.38 per ounce, with a mean of $34.55 per ounce, a median of $32.98 per ounce, and a mode of $30 per ounce.
I applied a swipe of foundation over each primer. At the very top, I included a control that had no primer whatsoever.
Next, I waited 12 hours. I was originally intending on doing a shorter test, but Kat Von D's Lock It foundation was too badass and made this impossible. (After four hours, there was literally no difference from when I first applied the swatches!)
As with the eyeshadow comparison, I was able to divide the tested foundations into three rough categories: low performers, medium performers, and high performers.
(Because none of the primers where I tested multiple versions significantly out-did their paired swatch, for the purposes of pictures I only used one of the two variations.)
Low performers: Hard Candy, Laura Geller, Bare Minerals, Pixi, Benefit That Gal
I classified these five primers as "low performers" because there was no visible difference between the swatches that were over these primers and the control swatch, which had no primer at all. Hard Candy is absurdly inexpensive, so it's probably not a big shocker that it was relatively ineffective. Prime Time, it could be argued, may be more effective for mineral makeup, since Bare Escentuals is a mineral makeup company. It is perfectly likely that they never tested their primer using liquid foundation. Pixi... I don't know. Maybe it extra, extra fixes your pores? Benefit's That Gal might be focusing more on brightening your complexion than prolonging your makeup? I have no excuse, even a contrived one, for Laura Geller's Spackle.
The one thing that it worth noting, however, is that none of these primers decreased the wear-time of the foundation. Thus, if you are using one for a reason other than prolonging the wear-time of your foundation (your pores or some shit), and you are happy with how long your makeup lasts, there is no compelling reason to switch primers.
Medium performers: Too Faced, Urban Decay, Makeup Forever, NARS, Paul & Joe, Smashbox, Mirabella
This category contained some of my favorite brands... and also Mirabella, for some reason. I would have expected a better performance from fancy-ass brands like NARS or Paul & Joe. Alas, it seems that fanciness is not a reliable indicator of performance.
Notably, the oil-free version of the Too Faced primer did better than its counterpart, although both still belonged in the medium-performing category.
High performers: Sephora Collection, Tarte Clean Slate, Tarte BB, Benefit Stay Flawless
The only real "what the fuck" in this experiment was here: WHY DID YOU DO SO WELL, SEPHORA COLLECTION?! I was definitely expecting the Sephora Collection primer to show up in the medium- or even -low-performing category. I was stunned when I checked my notes to see which primer was used for which number. That being said, the Sephora Collection primer isn't really saving you any money; It costs $30 per ounce, the same price as the Tarte primers, which also found their way into the "high performing" category. If you want a primer that will keep your foundation on and you ALSO want to feel fancy, you may just want to spring for the name brand and pick up Tarte.
The Tarte BB Primer also did really well, although I am suspicious of these results. Because it was tinted, I think that it may be the equivalent of just using more foundation.
Finally, Benefit's brand spanking new 15-Hour Primer held its own! It has polka dots on it, too, and I will always be happy when something with polka dots is successful. That being said, I think my 12-hour primer test demonstrated what companies really mean when they put absurd lengths of time on their products-- Benefit will certainly be doing way better than the control at 15 hours. However, there is marked fading. It doesn't look like the foundation was just applied at all.
I think that if you maintain realistic expectations, though, any of these four primers will probably serve you well. Unlike with my eyeshadow comparison post, though, there was no clear victor. Given the variation in people's skin, preferences, and goals for a primer, I don't feel like I can advocate for any individual product. However, if you are dissatisfied with how long your foundation is lasting, this may give you some avenues of exploration.