To be sure that any needlework item is the genuine article (as opposed to an inferior import or machine-made piece), look for a lead seal with an M, the emblem of IBTAM meaning it's been certified by the Instituto de Bordado, Tapecaras e Arte?­sanato da Madeira (Institute of Madeiran Embroidery, Tapestry, and Handicrafts), an official island organization that has a showroom/museum on Rua Visconde de Anadia, 44.
There is a seal to show authenticity.