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Two tutorials in a row? What on earth is happening??
Thanks to a reader email, I’ve been looking at matte top coats and DIY-ing them recently. Before we get to the DIY part, here’s how matte top coats work – it’s pretty simple!
Much like linear vs scattered holo finishes, it’s all about how smooth the surface is – in a glossy finish, the particles are uniformly spread on the surface in an even layer, and so the reflection is continuous. In a matte finish, if you zoom in to a microscopic level, the surface is rough and therefore the light bounces everywhere and you don’t get a smooth reflection – the light is diffused and scattered, which gives a dull finish.
The ingredient in commercial matte top coats that makes the surface rough is silica gel – the same as the stuff in those little water-absorbing dessicant packets, but ground up very very finely. (For those of you who like exact sizes, it’s finer than lab-grade 40-63 μm silica gel, which gave a bumpy, gritty finish when I mixed it with clear polish.) But silica gel isn’t that easy to get a hold of, and at a size that small, if you don’t have the proper equipment, it’s pretty horrible for your health (and if you get your hands on the wrong stuff, it can kill you in a painful way).
DIY Matte Top Coat
I’ve seen plenty of recipes floating around that give the two ingredients for an easy DIY matte top coat: cornflour (corn starch) and top coat. But I haven’t seen any with exact measurements, so I set about experimenting with quantities. I tried three different ratios of cornflour and top coat:
1/8 tsp cornflour in 1 mL Seche Vite
1/6 tsp cornflour in 1 mL Seche Vite
1/4 tsp cornflour in 1 mL Seche Vite
I firstly transferred 1 mL of Seche Vite to an empty bottle and added two bearing balls for mixing. I measured the cornflour using a 1/8 teaspoon kitchen scoop, and made a little funnel out of sticky tape and paper to assist in pouring (cornflour is pretty messy, and unlike glitter, doesn’t look so pretty on the carpet or your clothes). When I mixed the cornflour with the top coat, the result was a discouragingly opaque white gloop:
But when I swatched it, it ended up looking pretty impressive! I compared my cornflour frankens to the two commercial matte top coats I own, Rimmel Matte Pro and OPI Matte top coat. The base colour is OPI Incognito in Sausalito, from the San Francisco collection.
1/8 tsp cornflour in 1 mL Seche Vite is clearly the winner here – the finish is more satiny than the two commercial matte coats, but it’s definitely well away from glossy. Adding more cornflour just seemed to overload the top coat with solid clumps of cornflour particles, which made it crack or end up with white specks. 1/8 tsp per mL is as much cornflour as you can cram in there.
I think this might be more like the “wax” finish from Cult Nails than a true matte, but it’s possible that a different brand of corn flour, or even using other finely powdered starches (rice flour, or wheat starch) could give a different result.
If you’re playing at home, keep in mind that different brands of cornflour will be different (as well as different brands of top coat, and different lengths of time they’ve been open), so I suggest that you take 1/8 tsp per mL as a starting point and adjust accordingly. If you can’t get the cornflour to mix well just by shaking, stand the bottle upside down overnight and it should be much better in the morning.
(If you’re mathematically challenged, to work out how much cornflour you need, divide the number of mL of top coat you’re using by 8 to get the right amount of cornflour, in teaspoons.)
And if you have leftover cornflour, you can make fun slime!
Edit: Just realised there’s an apt GIF for this post! That’s cornflour, I swear!