The leather-soled men’s shoe may be equated with craft, quality and tradition but is it being usurped by a younger, more modern rival? According to a report at the Satra Technology Centre in Kettering, Northamptonshire, the rubber sole is on the rise. Between eight and nine per cent of footwear worldwide is produced with rubber soles, while leather accounts for just seven per cent.
The biggest advantage of the rubber sole is its “quality perception”, says Klaus Kjaersgaard, vice-president of global marketing for the footwear company Ecco, whose “Business Comfort” system of formal, synthetic-soled shoes has seen annual double-digit sales growth since its launch. “It’s less that the perception of leather soled shoes has declined, and more that synthetic-soled shoes have increased in line with improved quality and style,” he says.
Since Prada launched its first synthetic-soled shoes in the early 1990s, the idea that an upmarket shoe can exist without a leather sole has become increasingly accepted. “Leather is still a fantastic material to work with – which is why it remains the main material for uppers. It moulds to your feet,” says Tim Little, owner of the eponymous shoe brand that now puts a rubber sole on one-third of its styles. “But leather-soled shoes are less versatile, more expensive, and becoming more of a premium, niche item. Putting a leather sole on an upper is a long process and completely uncommercial,” he says.
Mario Polegato, chief executive of Geox, another big manufacturer of “comfort” footwear, agrees rubber soles have advantages. “A synthetic sole is lighter and more comfortable than leather, which needs to be broken in,” he says. “Leather is limited. It can’t be used on children’s shoes or on sports shoes – and they account for 50 per cent of global shoe sales.”
Indeed, the rise of the sports shoe in fashion has changed the consumer’s perception of how a shoe should feel: they now expect immediate comfort and the convenience of slip-resistance and full waterproofing. Synthetic soles (resin rubber or crêpe, PVC or polyurethane) increasingly play the eco card, too. The outdoor pursuits brand Patagonia, for example, has developed one sole made from recycled scrap rubber and another made of renewable hevea milk that is stitched on rather than glued, thus reducing the use of adhesives.
According to Urko Berrioaegortua Diaz, polymer engineer for Camper shoes, the brand that pioneered the sporty-formal hybrid shoe, a synthetic sole is simply the modern choice. “Craft, and hence quality, in shoemaking has long been associated with the leather sole because that was the only material available,” says Diaz. “Advances in industry have pushed what is possible with synthetics. Consumers may associate quality with leather but the idea that a rubber sole means a cheap shoe is fading rapidly.”
“It’s like the watch market,” says Alain Vilot, president of JM Weston, where rubber-soled shoes account for one-third of the spring/summer collection. “Now you can wear a gold watch or a plastic watch, and you may have both. Similarly, a rubber-soled shoe does not look out of place in business, as business dress gets more casual.”
“That’s true even with women’s dress shoes,” adds designer Rae Jones. “But there is some resistance, even if women may have more need for rubber soles because of the instability of many of the styles they wear.”
Perhaps the synthetic sole’s only disadvantage is that it is not naturally breathable, an issue that has been tackled by Geox by introducing a sole punched with microscopic air holes. And yet Geox has also recently developed its own leather sole, adding full waterproofing to its natural breathability. “There is still a demand for the leather-soled shoe,” says Mario Polegato. “I think leather soles will be increasingly relegated to special-occasion shoes. The question is, with generations coming through that make no such associations with leather soles, whether even that way of thinking will last.”