I’m always on the look-out for examples of the sneaky shrinking pack trend: that’s when manufacturers disguise the fact that a product has become more expensive by repackaging it in a slightly smaller pack, instead of doing the transparent thing and putting up the price of the existing pack.

Chocolate bars and slabs, tins of tuna, cooldrink cans, packs of tissues, tomato sauce packs – all have shrunk in recent years, to give us less for our money. Just a little, in the hope we won’t notice.

And when one brand does it, the others tend to follow suit, because if they don’t, they end up looking like the most expensive.

That’s because shoppers tend to look at the price only, ignoring the more relevant unit price, which reveals the price per kilogram or 100g.

For a while, I’ve wondered when a brand would buck the trend by announcing that while competitors’ packs are subtly shrinking, theirs was staying the same. As in a pack declaration “Still 100g!” or words to that effect.

Well, it’s happened, and the product is GlaxoSmithKline’s Aquafresh toothpaste.

The company began a teaser campaign with “Missing Something?” signboards in Johannesburg and Cape Town featuring scissors snipping through the end of an unbranded toothpaste tube; progressed to print and digital media; then went big with a “reveal” this week, accompanied by in-store and intersection giveaways of 25ml packs of Aquafresh with the note “Here’s the 25ml of toothpaste you’ve been missing”.

It’s a dig at the downsizing of Colgate toothpaste tubes from 100ml to 75ml, as reported in Consumer Talk last year.

At the time, I quoted a Colgate-Palmolive spokesman as saying: “Colgate is in the process of switching from a 100ml size to 75ml size tube for nearly all of our premium toothpaste products in South Africa.

“We do not set retail prices, but we have reduced the recommended selling price.

“The change in tube size was made to reduce consumers’ out-of-pocket expense, so that our high-quality toothpaste would be more affordable to more South Africans.”

As I commented at the time, the term “more affordable” should not be confused with “cheaper” or “better value”.

GlaxoSmithKline’s consumer healthcare marketing director, Liezel Sabbagh, told Consumer Talk that while the rising cost of raw materials made price increases inevitable, “we’ve taken a decision to do it transparently”.

“When a big player in the market downsizes a pack, there is naturally a lot of pressure on the rest of the players to follow suit,” Sabbagh said.

“But we felt that following this trend wouldn’t be true to Aquafresh’s brand values.”

The brand’s advertising agency is laying it on a bit thick, hailing the brand as the “consumer’s champion”, “hero” and “white knight”, but any initiative that focuses consumers’ attention on pack shrinkage is a good one, in my view.

Remember, it pays to get into the consumer-wise habit of comparing not only shelf prices, but unit prices.

Pick n Pay and Shoprite group stores display unit prices on each shelf tag, but neither Spar nor Woolworths stores do this. I’m going to add an optimistic “yet”.