Should I send a paper copy of a contract to my clients?

No, this is not necessary. Electronic signing (e-signing) is convenient and legally-binding. When you use a reputed e-signing platform, the e-signature can be traced to your client’s IP address, which can offer proof of who signed a contract should it be required (signatures can be forged). However, if you prefer a printed and signed copy, there is no reason why you shouldn’t have one!