Somewhere in the stacks of the Natural History Museum in Leiden, between folio pages of hand-pressed rag paper, sits a Saturnia pavonia that Gerrit Lambertz coloured sometime in the winter of 1778. The wash is a warm sienna over the engraved line work — not painted freehand, but dabbed in layers with a squirrel-hair brush, each coat allowed to dry before the next. I spent two weeks last autumn with a loupe pressed to my eye, tracing the registration marks where his pigment met Cramer's burin lines, and I came away convinced that no mechanical reproduction has ever matched it.
The Workshop at the Keizersgracht
Pieter Cramer's house on the Keizersgracht in Amsterdam was not a laboratory. It was a counting house where a textile merchant kept his specimen cabinets, and the artists who coloured his plates — Lambertz foremost among them — worked in a back room that smelled of gum arabic and wet paper. The plates for De uitlandsche Kapellen were printed in small runs, each sheet drying for days before a colourist began the slow work of sienna, umber, and cream-buff wash.