Flag of Canton of Valais (Switzerland). The black contours around the stars and along the division of the field are not usually seen in cantonal flags and are an artefact of this representation reflecting the image used for the pdf of the federal Fahnenreglement of 2007.
Own work using: the federal Fahnenreglement  Regl. 51.340 d  of 2007.
This  vector image was created with Adobe Illustrator.