XPS Polystyrene BGX1 COVING LED Lighting System Cornice, Moulding, Sidelighting, Indirect Lighting, Ceiling coving Decoration, Home Decor, Quality Product (15, 100mm x 50mm)

Installed as advised. Looked lovely until we put the lights on, then could see all joins and lots of adhesive. Tried painting the coving, but after 3 coats it was somewhat improved but still very obvious joins. Have read that it might help to foil line the cavity, but frankly I don't think this product is fit for the purpose it was sold for.