SPM Mug by Rörstrand. Enjoy a cup of tea in this beautiful mug with linen structure. It belongs to the SPM series, which stands for Signe Persson-Melin, who is also the designer behind the success. The mug has a warm gray tone that gives both a modern and timeless feel, and fits perfectly for both everyday and party. It is made in porcelain and is dishwasher safe.