All Oliver's original watercolours have been painted on 100% cotton, acid-free paper of the highest quality from Daler Rowney and St Cuthbert's Mill in Somerset, UK. Oliver has chosen these papers not only for their ability to provide the optimal painting surface, but for their exceptional presentation of colour, and resistance to discolouration. All paints used are Artist's Quality from Daler Rowney, offering the best clarity and light-fastness available.

Each original painting comes with a signed Certificate of Authenticity.