Sheffield Pottery began with a farm and a pit.

Sheffield Pottery’s story starts with a purchase and a bucket. “In the fall of 1943, Joseph and Marie Cowen, newly married, purchased a large farm near the Housatonic River,” the company says, in Sheffield, in the south-west corner of Massachusetts. They “hauled a bucket of clay from the clay pit on their land” — and the farm’s clay became a business. By 1946, it says, the animals were gone and the barn had become a showroom with a six-foot kiln; in December 1949 the pottery was featured in Redbook magazine, an early sign that a farm pottery in the Berkshires could reach a national readership.

The family business grew in steps. “They incorporated” by 1965, the company says, and in 1982 Joseph Cowen retired and passed the business to his youngest son, John, who is still president; the Better Business Bureau lists him as such, and dates the business to 1946. New buildings followed: a warehouse in 1983, a 14,000-square-foot facility in 1993 and another 12,000 square feet in 2000–01. The company is Sheffield Pottery Inc.

It became a clay maker rather than only a pottery. Today it sells clay bodies, glazes and materials to potters and schools, and it mixes its clays, it says, in a “world class Eirich mixer,” screens them through a Sweco separator, and uses an iron-filtering magnet that it says is “used by no other clay maker in America” — its claim.

“Natural Sheffield Clay is mined on our property.”

What makes Sheffield Pottery unusual is the pit. “Natural Sheffield Clay is mined on our property … The Sheffield Clay deposit is located in Sheffield, Massachusetts, on U.S. Route 7 in the Southwest corner of Berkshire County,” the company says, and describes the deposit as “approximately 300 feet deep and … located on a 16 acre site.” Many studio clay makers buy all their raw clays; Sheffield digs at least some of its own, on the farm the Cowens bought in 1943.

It names the bodies that use it. The 4DS and 4DSM stonewares, Mass Red terracotta, MGB earthenware and 94600 Black Earthenware are made with what it calls “our native Sheffield clay” or “locally sourced Sheffield Clay.” Its range also includes bodies built from bought-in clays — Elaine’s Crystal Grolleg Porcelain uses English china clay — so we do not say all its clay comes from the pit. Its other bodies — Berkshire White, 413 Birch White, Liz’s Light, 95400 School White and 45R Raku among them — fill out a range for every kind of studio. It also sells an Albany Slip substitute made from “a native glacial clay,” noting that the original Albany Slip mine “closed in 1986.” Albany Slip, a natural brown glaze clay from New York State, was a staple of American potters for generations; its loss is a reminder that a named clay can simply run out.

The pit has uses beyond pottery. Sheffield also sells clay by the cubic yard for baseball infields, pond liners and horse stalls, and cites a regional school’s ballfield among its customers. A clay deposit, in other words, is a farm crop with many buyers.

Where America’s clay comes from.

Sheffield’s pit is tiny by national standards. The US Geological Survey estimates that American clay production “was estimated to be 26 million tons valued at $1.8 billion in 2025, with about 120 companies operating clay and shale mines in 38 States.” Its estimates for the two clays potters care most about were about 990,000 tonnes of ball clay and 4.8 million tonnes of kaolin in 2025. Most of it does not go into pottery: the same report puts ball clay’s leading use at floor and wall tile, 53 per cent, and kaolin’s at fillers and binders, with 20 per cent going to ceramics. About 1.6 million tonnes of kaolin were exported, mainly for paper. The average value at the mine was about $47 a tonne for ball clay and $170 for kaolin — cheap materials whose value lies in selection and blending.

The big deposits are elsewhere. The USGS’s 2019 yearbook says ball clay was produced in five states, led by Tennessee — with tile taking 55 per cent and sanitaryware 18 per cent of domestic sales — and that “Georgia accounted for 92% of the U.S. kaolin production.” A typical studio clay house blends clays like these, bought from large miners; Sheffield’s own pit, in a Massachusetts river valley, is the exception that makes its brand. The British Geological Survey explains why blending matters anywhere: it “reduces the natural variability of the clays.”

A native clay is variable by nature, which is why Sheffield’s mixer, screens and magnet are part of the story: they are what turn a farm pit into a product a potter can trust from bag to bag. Variability is not hypothetical: in this round, Standard of Pennsylvania warns customers on its homepage that a supplier “has been mining the RedArt clay from a different seam in their mine,” so the fired colour of many of its bodies may vary. Sheffield sells the same Cedar Heights clays — Goldart and Redart — alongside its own, so the two companies draw, in part, on the same supplier’s clays — and on the same variability.

A place name that is also an ingredient.

Sheffield Pottery’s brand is a place name that doubles as an ingredient. “Sheffield clay” on a bag means a town in Massachusetts and the clay dug there; few brands in this series can say that their name is literally in the product. Its body names add local colour — Mass Red, Berkshire White — and its history gives the brand its voice: a farm, a bucket and a barn.

For a design guide, Sheffield shows the power of a short supply chain told plainly. Where Potclays and Valentine in this round name distant counties, Sheffield can point across the yard.

We could not verify Sheffield Pottery’s logo or colours, so for this guide we use a Massachusetts red and a pale terracotta with a farmhouse serif. These are an unofficial interpretation, and nothing of its marks is reproduced.

Keep Sheffield Pottery’s identity on hand — save it to a board in the Made Good inspiration library.