In a 2004 interview with Radio 4’s World At One, David Cameron, then head of policy co-ordination for the Conservative Party election campaign claimed that “people are crying out for a kind of Ronseal politics. They want it to do what it says on the tin.” The phrase he invoked was, by then, ten years old but it was well known in the UK to the point of being idiomatic. Today, many people are still surprised to learn that the expression ‘it does exactly what it says on the tin’ actually originates from an ad campaign written in 1994, and that it hasn’t been part of the common language for much longer.

The no-nonsense, straight-talking line now has its own entry on Wikipedia (only a few slogans featured on our list can lay claim to this) but back when Ronseal briefed agency HHCL & Partners to come up with a new campaign for its Quick Drying Woodstain, the intention was simply to convey the functionality of the product and differentiate it from a host of newer ‘lifestyle’ and interior design-oriented finishes, varnishes and treatments.

“Ronseal knew what they didn’t want – an artsy ad,” explains Dave Shelton, who created the campaign with Liz Whiston. “The brand had been around for ages, it was workmanlike not trendy. And they wanted something that was straight, literal and that got to the point.” However, it was only after initial discussions had taken place that the agency realised there was a deeper problem which the brand would need to address.

“When people walked into a DIY warehouse and went to the woodstains and varnishes section they were confused,” says Shelton. “They were afraid of using the wrong thing.” HHCL’s approach was to “demystify the process of buying the product” and, says Shelton, the team came up with the simple conceit that “if you had wood to stain, and needed it to dry quickly, then you needed this quick-drying woodstain. There’s no magic to it.”

That said, it was the endline to the TV script that Shelton and Whiston were working on that eventually became the magic ingredient to the whole campaign. “The actual line just came from the formula ‘this-does-that’,” says Shelton. “It felt like the perfect way to end our script.” But even within the agency, Whiston recalls, the line was thought of as a ‘working endline’ that would be improved upon in due course. “I was asked quite a few times by planners to write more endlines for the campaign,” she says, “but I decided not to because I loved it as it was.” Yet, Shelton reveals, when it was put into research the spot was uniformly disliked.

“People thought it was dull,” he says, “but Ged Shields, Ronseal’s marketing director at the time, loved the script and stood by it.” To read it on the page the text is full of repetition and seemingly obvious-sounding statements, veering towards tautology (eg “It protects and is rainproof in about 30 minutes. Which means in about 30 minutes your wood’s rainproofed and protected.”). But this is precisely what makes it work. It’s as straight-talking as the product.

This also meant that the casting in the ad was crucial. With the script in the wrong hands the tone of voice could easily have come across as smug or condescending. So rather than the inner sanctum of the hardware store, the scene is unthreatening suburbia and features a regular DIY-er who’s keen on home improvement, not a professional. “These kinds of products can be seen as intimidating,” says Shelton. “But this was trying to encourage people, essentially saying ‘don’t worry, it’s just a varnish’. And that’s the sentiment: that anyone can do it.”

More widely, as HHCL’s then creative director Steve Henry suggests, “the campaign went against the grain of all the clever advertising around at the time. So it stood out massively and had an emotional connection with people, precisely because it wasn’t a typical piece of advertising confection.”

Ronseal went on to trademark the line, which is still in use across a range of its different products.

Its influence over the DIY market is pervasive, too. Wickes’ ‘It’s Got Our Name On It’, for example, owes much to the salt-of-the-earth philosophy originally employed by Ronseal. The phrase is even listed in the Oxford Dictionary of English Idioms. Not half bad for a line that does, well, you know the rest.

Discover more of Creative Review’s top 20 slogans