The classic support is, as already mentioned, linen, although half-linen is accepted, in which the warp is made of cotton and the weft of linen. Likewise silk can be accepted, as with historical pieces.

However, other media can be considered as innovation. Such is the case with the fabrics used in the garments decorated with Castelo Branco embroidery. What is certified is the embroidery, and as long as it is identifiable, by design, by material and color, by the stitching used, it matters little - in the case of clothing - what fabric it is embroidered on.

In the field of home textiles, other textile backings will be permissible on items such as duvet covers, pillows, curtains, or valances.