Brusca is a breed- and flock-specific yarn made of 50% Saloia and 50% Merino Branco and Merino Preto wool. Saloia is the native sheep breed to the region of Lisbon and Setúbal. It is well-documented since the 19th century, as its wool was one of the finest available in the country. Saloia sheep have also become famous for their milk, from which the famous Azeitão cheese was traditionally made. Brusca is made from the wool of free-range sheep.

Retrosaria Rosa Pomar makes minimally processed, heritage wool yarns from Portugal. Their yarns are created in collaboration with small manufacturers, breeders associations, and shepherds. All Rosa Pomar yarns are non-superwash, not bleached, have no silicone-based softeners, and mulesing is not practiced in Portugal.