Thinflation - rants - mitxela.com

Thinflation<br>6 Dec 2025Most people have experienced "shrinkflation" in one form or another, where manufacturers, in lieu of increasing prices, subtly reduce the quantity or size of a product, keeping the packaging mostly the same, in order to deceive their customers into buying less for the same price.

Crucially, the reductions must be craftily applied so that the majority of buyers don't notice. It's understandable that people froth with vitriolic effluvium when they arrive home to find that their favourite snack has been permanently altered for the worse. It's a balance of greed against grievance, to dance along that fine line so that the collective anger and disappointment flies under the threshold of brand loyalty destruction.

No doubt there are highly paid consultants whose entire careers have been built on this lucrative legal deception.

I don't have too strong a reaction to it, at least when it comes to those edible homogenous media like chocolate or cheese. Sure, maybe the portion size is now impractical, but in the end it's simple enough to keep a watchful eye on the price per unit mass, and figure out if we're getting that elusive Good Deal. Or the degree to which the proposed deal is actually Good.

Maintaining a mental chart of the acceptable volumetric costs of common goods is one of the small prices we pay for living in a western capitalist society.

People hate shrinkflation, and with good reason, as loud complaints are the only thing that can keep it in check. But today I'd like to talk about a related problem, one that no-one seems to be complaining about, one where the Bad Guys have won.

Soap

Perishable foods are one of the few categories of product where disposable plastic packaging makes a huge amount of sense. The environmental cost of wasted food far outweighs that of the plastic film that could preserve it.

The same cannot be said about soap.

Cleaning products – handwash, laundry detergent, shampoo, etcetera – have a near infinite shelf life, and there is no reason not to buy them in bulk. Perhaps you might want to experiment with different brands, sample this one and that, but once you've found a product that you like, stocking up on a few years' supply has no downsides... for the consumer.

But bulk purchases are a disaster for the companies behind Big Soap. They want to sell you as little as possible, as often as possible, to lock you into their endless marketing cycle, and they manage this by playing on a peculiar psychological trait we all share.

The Thin Situation

Humans are bad at judging volume. Given two differently-shaped glasses of liquid, most people are completely unable to guess which one holds more. The variation in the shape of pint glasses, which all hold the same volume of liquid, goes some way to illustrate the extremes of the effect.

These three cylinders all have the same volume:

Even if you remind yourself that it scales by the square of the radius, judging the volume of a cylinder doesn't come naturally to us. And for complex shapes it gets substantially harder. The shape with the largest volume, for the smallest apparent size, is a sphere. Or arguably an oblong, viewed only from the end. Conversely, the shape with the largest apparent size for its volume, at least if we stay within the confines of what can practically be turned into a container, is a thin, flat blob oriented towards the viewer. And this is precisely the shape soap bottles are striving for.

This handwash bottle is 85mm wide, but only 35mm thick, dictated by the diameter of the screwcap. If thinner pump mechanisms were available, they would no doubt have made the bottle thinner still.

Am I the only one who finds this ridiculous?

They recently reduced the volume of these washing-up liquid bottles, by about 30mL – standard shrinkflation – but they managed to keep the width and height almost the same as the older bottles. There is even an indent in the middle section to make it thinner.

The cost of retooling the moulds is substantial, but obviously insignificant compared to the increased profits proffered by such thinness.

Defences

Once I recognised this behaviour, which I have dubbed "thinflation", I started to see it everywhere. It is a contagious marketing technique: if your competitors make their bottles thin and flat, they visually look bigger and will sell more, so every manufacturer has to race to make their bottles as thin and as flat as they can get away with.

But what confused me is that nobody else seems to have noticed. In fact, people are so conditioned by the now-expected shape of a soap bottle that they will go out of their way to rationalise it. I met a bloke in the pub who insisted the shape was justified, reeling off multiple arguments, which I shall now dismantle.

"they pack more efficiently, they're easier to transport"

This is simply untrue. The most efficient shape for transport is a cuboid. For instance, Tetrapak cartons...