Technology changes fast, in the world of women's lingerie as much as anywhere The latest 'tech-forward' bra to grace Hong Kong's lingerie stores is the NuBra - skin-coloured silicone pads that stick to the skin without any back or straps. 'We've had silicone pads in our shops before but these are different because you can use them as they are without glue or straps,' said a spokeswoman for lingerie chain Private Shop. 'Customers say they are pleased with the product, that they fit well and look very natural under any types of clothes,' she said. 'The clip in the middle also helps to enhance the cleavage. 'But they don't come cheap at over $1,000 per set. And so many women still prefer to buy older products which need to be stuck on with glue but only cost several hundred dollars.' Jillian Tong, owner of Jillian Lingerie in Wyndham Street, said that the self-adhesive pads were selling well. 'Summer is here and women want to wear less in the hot weather,' she said. 'Women who are quite slim and not particularly full are attracted to the product.' The NuBra's stickiness is provided by a film of polyurethane on the inside of the silicone cups. Derived from crude oil and discovered more than 50 years ago, polyurethane is a type of plastic used to make a wide range of products, from shoe soles and lycra to superglue, said Chan Wai-kin, an assistant professor in chemistry at the University of Hong Kong. But he said people with sensitive skin who normally find wearing synthetic materials uncomfortable might also be allergic to polyurethane products. Private Shop said they had had no complaints about the product so far. A spokeswoman for bra-maker Wacoal said they had no plans to launch similar self-adhesive products, but added: 'We are concerned about any possible skin allergies our customers might experience.' NuBras are made in the US by Siliconeworks International, whose other products include 'Le Nips', dubbed 'the ultimate silicone prosthetic nipples' and 'the Fluid Fulfilment water bra'.