Miracle cure or cosmetic rip-off? At pounds 18.50, we thought Yves Sain t Laurent's light-reflective make-up for instant radiance should be put to the test
There are two things we know for certain in this ever-changing world. One is that we are all going to die, and the other is that luxury cosmetics are never, ever, intrinsically worth what we pay for them. While the difference between a designer jacket and a high-street jacket can be hundreds of pounds, the difference between the top and bottom ends of the make-up market can be, say, pounds 15. Shutting our eyes to the "rip- off" factor, we part with pounds 20 for the little bit of glamour fancy packaging can give us.

You're certainly paying for glamour with Touche Eclat, Yves Saint Laurent's anti-dullness cream. At pounds 18.50 you get a 2.5ml (that's 0.1 floz) of water mixed with various emulsions all wrapped up in an elegant, gold, cosmetic "pen". The cream comes out of a brush at one end and is released when you push in the other end until it clicks - just like a posh ballpoint pen.

Paint the cream on dark circles under your eyes or either side of the bridge of your nose. But don't put Touch Eclat on your spots, because it's a highlighting cream, not a concealer. Instead, emphasise cheekbones or do a Marlene Dietrich, where you draw a line of highlighter down the middle of your nose to make it look slimmer (if it worked for her Slavic nose, it can work for you). Touch Eclat comes in one colour, "Rose Lumiere", which claims to blend into all skin colours and, having experimented on a few friends, it seems to do the trick. But is it worth pounds 18.50?

Richard Hawkins, training manager for YSL, points out, "You get 200 applications full of product in each Touche Eclat. It costs less than 9p a day to use. The other benefits are that it has an instant face-lift effect, where it softens lines, because it's light-reflecting." This is due to Luminocaptide, apparently, a special mixture of pigments and oils exclusive to YSL. "As skin gets older it loses the ability to reflect light," explains Hawkins. "Touche Eclat brings it back, but with a matt finish."

So what do the experts think? "It reflects away all the shadows so you can't see the bad bits," enthuses make-up artist Charlie Pichon. "I use it on models a lot because you can play with the shadows. It lifts cheekbones forward, and if you put it on the chin, it sticks out more. The only problem is that you never know when it's going to be finished so I always carry two. With one click it ends and you don't notice it's running out, so, suddenly, it doesn't work".

You wouldn't have such problems with L'Oreal's Magic Conceal which, at pounds 4.29 for 1.5ml, claims to brighten the skin. It comes in two shades and is wrapped up in nasty pink and gold packaging. The foam applicator does not blend the colour as well as Touch Eclat and if your skin is dry, Magic Conceal makes it even more flaky on application. OK, you're paying for glamour, but Touch Eclat, at 9p a day, really works and is almost worth the money.