Lot 40059 – 1866, 50r blue on bluish paper, featuring the “filigrana de sutura”

1866, 50r blue on bluish paper, featuring the vertical “filigrana de sutura” (“suture” or “stitch” watermark), presumably unused without gum, couple of surface scuff spots, not detracting from this most probably unique watermark variety on bluish paper; ex Dr. de Amaral Machado.

Note: The “suture” watermark is caused by the splicing of the felt that carried the wet paper -during the process of its manufacture-, which was made with metallic threads. It is an accidental filigree with the appearance of a suture, when the stamp is examined in benzine.