Marco Lewis scores his pots with the tip of his modified slip trailer before making slip dots.

Marcos Lewis used to live in the Pacific Northwest where he worked as a commercial fisherman. Although he moved inland long ago, he remembers the texture of sea urchins and has captured that texture on his pots.

In today’s post, an excerpt from our newly updated free download Five Great Pottery Decorating Techniques: A How-to Guide for Decorating Ceramics with Slip Transfers, Chinese Brush Techniques, Ceramic Slip, Sgraffito, and More, he describes the tools and techniques he uses to re-create one of Mother Nature’s most distinctive textures. – Jennifer Harnetty, editor.

Marcos Lewis’ Sea Urchin vessels are inspired by the time when he lived in the Pacific Northwest working as a commercial fisherman. “All my years, first as a kid on the beach digging clams, looking under rocks, and later working as a commercial fisherman, have filled my memory with shapes and patterns,” he states. Marcos has been making sea urchin forms for about seven years and he has developed a process and a few tricks along the way that he’s happy to share.

Marcos throws his urchin form on the wheel, using a rib to form the inside, then closes the form until only a tiny hole remains on top (figure 1). He throws with very little water in order to trim and decorate as quickly as possible. Once the piece has set up to leather hard, he places the pot back on the wheel and brushes the inside of it with a white slip. He then trims the outside of the form to match the space he created on the inside, taking care to leave an even wall (figure 2).

After trimming, Marcos uses a ball syringe with a piece of an ink tube from a ballpoint pen fitted into the end to slip trail the textured bumps similar to a sea urchin. As he trails slip, he scores the surface of the pot with the tip of the ball syringe for better adhesion (figure 3). “When making the beads of slip, I tend to poke and jab the plastic tip of my trailer into the clay, this makes small cuts and dents in the clay under the slip and gives the slip a rough scratched surface to adhere to.

I also sometimes go back and gently press the bumps onto the clay as they dry if I see some separation happening,” he notes. When his syringe is not in use, he uses a piece of guitar string to plug the hole. He joked, “It’s ironic that when I was a commercial fisherman in Alaska, I used to keep my hands in shape when not fishing by squeezing a rubber ball, now I make my living by squeezing a rubber ball!”

Large urchin form made from dark brown stoneware and porcelain slip, glazed with a green celadon; two smaller urchin forms, both made from porcelain and porcelain slip, one with a pale blue celadon, and the other with a clear glaze.

Laying out the patterns by eye, Marcos makes a first line of bumps from the top of the pot, straight down the side of the pot, then does the next line directly opposite the first. By eye he finds the halfway point between two existing lines and continues his decoration around the pot, but he doesn’t always stick to straight lines. He’s made a special tool to clean up around the bumps if he needs to; he simply ripped the foam rubber off of a disposable paint brush, and cut the plastic support inside down to the exact shape and size he needs. “This is also a good tool for cleaning up around handles,” he said (figure 4).

Marcos is experimental with his clay bodies, slips, and firing methods. He’ll run the gamut from using a white porcelain slip on a dark clay body and creating an atmospheric effect with soda ash, to a stark white on white with a clear glaze, and everything in between. He’ll even modify the density of bumps to get particular effects from ‘stunt glazing’. “I pretty much use any combination [of clay, slip, and firing] I can get my hands on, low fire, micaceous, standard high fire, reduction, salt, soda, etc. If there is any. . .combination that I haven’t tried yet, then I plan on it!”