Cufflinks by Kate Smith Contemporary silver cufflinks by Kate Smith. The pattern is achieved through a process called acid etching. A permanent colouring (known as oxidisation) is then applied into the etch to give a beautiful, contrasting colour between the black and the silver.These striking silver cufflinks have beed designed and handmade by Kate Smith.Also available with gold detailing. Features Primary Material : silver Other Materials : oxidised colouring Fitting Type : hinged bar Dimensions (mm) : 18x11x1.5 One of a Kind : No Metal : sterling silver Hallmarked : Yes Cleaning InstructionsPerfumes, lotions and chemicals can all affect the look of jewellery over time.Using a soft (old!) toothbrush and warm soapy water can remove build-up of dirt/discolouration.Using hairdryer (on a low setting) afterwards will help to avoid water marks on your jewellery.Avoid contact with harsh chemicals, especially when wearing jewellery with gemstones.Wearing your jewellery (rather than keeping it hidden away in a box) is the best way to avoid tarnishing on silver! Your skins natural oils help to form a barrier against oxidisation.If you find your item of silver jewellery blackens when you first wear it, follow the above method of cleaning with a toothbrush & warm, soapy water.Initial discolouration should fade within time. It isn’t clear why this can happen to some people’s jewellery, but from researching, it seems it could be attributed to medication, diet or even pregnancy! (If you are male, you can probably rule out the last cause).FinishesFinishes that are applied to our jewellery can alter over time, simply due to everyday wear. This is more applicable to rings and bangles; satin & frosted finished pieces may become shinier with wear and polished items can become slightly duller with time.