CP, Canadian porcelain 10 inch porcelain suspension in their metalic tan colour. What appears as an ordinary inkstamp is an illusion. A unique feature of this disc is the disc is embossed - located underneath on the outer rim of the porcelain. Not only embossed but it is highlighted with black glaze ( ink ?) as well. There are several embossings; the four described here, another with just '1942' and another unembossed.