Encyclopedia
Macis
b) mace, which is a fibrous covering of the nutmeg between the outer shell and the kernel. This substance, when cut into strips, has the same properties as nutmeg but even more pronounced. It is bright red in fresh condition, but over time it turns yellow and becomes brittle and semi-transparent like horn. Sometimes mace may be straw-colored or even white;
Source: "Explanations to the Commodity Nomenclature of Foreign Economic Activity of the Russian Federation (HSN Russia)" (prepared by the Federal Customs Service of the Russian Federation) (volume 1, sections I - VI, groups 1 - 29)