NEW YORK — It’s all in the details. Fur designers presented looks this week, organized by the Fur Information Council of America, and the prevailing trend this season was in treatments and mixes. Carmen Marc Valvo, for example, worked neat pleats into sheared mink boleros or coats as well as bold intarsia in long, easy jackets that mixed brown mink and black lamb. Ekso for Alexandros also offered mixes, such as the cozy duffle coat that combined fur and cotton, and Helen Yarmak fused leather and fur in her beautiful sable-hooded jacket that reversed to rhinestone-edged brown leather. Red was the color of the season, as seen in Adrienne Landau’s embroidered shearling jacket trimmed in lippe cat. And soft, casual knits were ever-present this week; one of the best was Landau’s knitted mink ruffle-edged in white.