As I've mentioned in earlier posts, the truly exceptional aspect of the Mermaid's Grotto piece is the extent to which the designer (Tricia Nguyen) has faithfully recreated the 17th century techniques and materials in the piece. My favorites are the "coral rocks" and the "moss rocks".
Here are close ups of the two coral rocks:
I really love the effect here. To my mind, they truly look like coral!
Making them is a multi-step process. . . starting with gylt silk twist thread and silver gylt twist thread. (These are threads that Tricia had made during the Plimoth Jacket project, and are silk cores with a gold or silver gilt metal wrapped barber-pole style over top.) To make the threads for the coral, the gyte twist thread is wound around jewelry wire, then the wrapped wire is wrapped around a milliner's needle. The resulting coiled thread is then removed from the needle, and couched down to create the rocks. Making this thread was relatively easy, and I think the effect is just fabulous.
My other favorite rocks are the moss rocks, shown below. These are stitched using a single strand of Soie de Paris thread. Tricia calls these drizzle or moss rocks, but I'm not sure what to call the stitch. Basically, you just twist the thread until it's very very tightly twisted, and will coil up on itself if tension is released. Then the needle and most of the thread is taken to the back of the fabric, leaving the loose thread left on the surface free to twist and coil up. I love this effect too, but stitching it was very slow and tedious . . . but definitely worth it.