Pros: Magnetic clasps are the easiest type of clasp to fasten, so are ideal for bracelets, but also great for necklaces, especially if the jewellery is going to be worn by someone who struggles with small fiddly clasps.
Cons: Magnetic clasps are often more expensive, although, arguably, this is a price worth paying. Be careful to select a reputable brand (try it for yourself) or you may find that you are buying a magnet that is too weak to create a secure fastening. When used for bracelets, be careful as the clasp will attach itself to any metal object in its vicinity and I have heard stories of people losing bracelets on handles of shopping trolleys or metallic door handles, without realising the loss until hours afterwards. Most of all, heed the warnings that should be on the packet – magnetic clasps can interfere with the workings of watches and pacemakers, so never wear a magnetic clasp if you are fitted with a pacemaker. If you are selling jewellery made with a magnetic clasp, make sure that you label it with a clear health warning to this effect. It can be embarrassing asking customers if they wear a pacemaker, but do try and find a diplomatic way of doing this if you can – it is far better than being responsible for a serious health issue!
From a design perspective I love the versatility of magnetic clasps. They come in different styles, so you can find a clasp that will suit the style of your design. However, I particularly like to use magnetic clasps concealed within beadwork, so they really blend seamlessly into a design. The most ambitious project of this type I have tried so far was my Battle of the Beadsmith necklace of 2013, in which I found a large magnetic clasp to conceal within a beaded pack of cards. There are plenty of options though, so don’t feel restricted to using magnetic clasps like you might other metal clasps – there are plenty of clever options available.