I recently bought some adorable postcards in Paperchase and turned them over to see who the artist was. Belle & Boo is the work of illustrator Mandy Sutcliffe:
"Belle & Boo are two of Mandy’s favourite characters. Belle with her bobbed hair, bright eyes and wearing vintage clothing, is insistently curious about the world around her, and based on elements of Mandy as a child.
With her magical imagination Mandy was always surrounded by friends, and together they fulfilled many a daydream. So when creating Belle she gave her Boo - Belle’s adorable bunny rabbit companion and confidant."
I discovered she has a website www.belleandboo.com where you can purchase prints of her adorable art along with bags, buttons, clothes, tags and cards etc.
She also has an adorable blog where she posts pics of the original drawings.