Copyright© belongs to the 'artist'. Copyright arises automatically in UK law and requires no registration or other formality.  All artistic works are protected against unauthorised reproduction, publication and commercial dealing.

Artists works created since August 1989 are given uprated protection by the Copyright, Designs and Patents Act 1988.   Works made after 1989 are protected for the lifetime of the artist, plus 50 years after death.
Be aware that after the sale of any work, the artist retains the copyright, unless specific arrangements are made.