Salt-glazed traditional Jugtown-style pottery by Karl Martz, 1957, made at the Jugtown Pottery.
These pots have a "J" near the signature, signifying that they were made while Karl was visiting the Jugtown Pottery (North Carolina). Below is Karl's account of his visit to Jugtown. Here is another example of his work at Jugtown.
A pitcher similar to those pictured above sold on ebay in 2004 for $1,148. See Auctions.
Jugtown Pottery and Karl Martz's Visit in 1957
Carolina Antiques and Collectables states:

Ben Owen (1904-1979) founded the Ben Owen Pottery, currently operated by Ben Owen III. At their website you can find more about the history of the Jugtown Pottery.

Karl & Becky's son Brian Martz recalls Karl mentioning that the potters at Jugtown walked with a limp resulting from years of using kickwheels.

Here is Karl's personal account of his visit to the Jugtown Pottery. The year of this visit is known to be 1957 because of a letter found among Becky's archives, written by Karl to her while he was at Jugtown -- the postmark on the envelope is August 19, 1957, Seagrove N.C., next to the 3-cent stamp. Karl wrote the account below decades later.

Harvey Littleton wanted to learn about salt glazing so he contacted Mrs. Busbee at Jugtown and she invited Harvey and me to come and observe a firing to see how their process went. In about the summer of 1954 [actually 1957 -- see above] Harvey and I drove to Jugtown with a tent and equipment. Somehow I arrived without anything, so Mrs. Busbee, who owned the pottery, let me stay in the house.

They had a horse-drawn pug mill run by Mr. Whitaker. Ben Owens was the master potter. Harvey and I threw a number of pieces -- some in stoneware for salt glazing and some in a red clay for what they called their red ware. They dug up the stoneware clay nearby and some big terra cotta company had purchased this clay deposit and the Jugtown potters were having a hard time getting good clay to use. They put it through the pug mill just as it came which made it moist and plastic. Each person would take about a ten pound lump of clay and slice it with a wire fairly thin; then examine each slice and pick out the pebbles. At that time Mrs. Busbee was proud of the fact that they were using colonial methods. The picked clay was probably worth its weight in gold. It was kept in a pit in the potting shed covered with wet burlap. Everybody knew where his lump was and not to bother anybody else's lump. The only concession to the twentieth century was a single electric light bulb hanging from the ceiling. We threw on treadle wheels. They had very heavy wareboards about 2 by 8 and 8 or 10 feet long.

The pieces were then dried and fired in ground hog kilns -- one for salt glaze and one for low temperature redware. The only access to inside the kiln was climbing through the fire mouth. A person would stand outside the kiln, one in the firebox and one inside. The pots were handed from person to person and the one inside would place it in the kiln. [See photo of Ben Owen Sr. doing this.] There were no shelves. The pots just sat on flintstone gravel, fractured and sharp so it served as a kind of stilt. There was one level of of pots from firebox to chimney. Kilns were about fifteen feet long and about six or seven feet wide. The chimney was the full width of the kiln and not very tall. Kilns were set into the hill. Then the ground rose up even with the top of the kiln. We could walk around and look in the chimney.

The kilns were wood fired. Red ware was glazed with high red lead glaze which tended to settle out all the time so you had to stir it. Fired to approximately cone 05 or 05. The salt glaze was cone 11. The kiln was started in the morning and went late into the night. The fire mouth was about two feet squeare and never bricked up. A sheet iron hung over the front of the box, was swung over to the side to stoke the kiln. Then swung to cover the box again. Salt was dropped throught several holes in the roof in the arch of the kiln. The holes were covered with bricks. We shoved them to one side and poured a dipper full of rock salt in. Some pieces under holes came out of the kiln half full of melted salt and had to be soaked to get the salt out.

Altogether we spent about ten days throwing and firing. Mrs. Busbee cooked for us. She was very welcoming and hospitable. We offered to pay her when we got ready to come home, but she said just our being there was pay enough.

They had a source of moonshine whiskey and they gave each of us enough to fill a little whiskey jug we had made, salt glazed. Although the jugs were fired to cone 11, the whiskey slowly evaporated away. In all my pieces I tried to copy their historic designs which went back to the Civil War, or perhaps earlier. Potters were exempt from service because their wares were needed in hospitals and camps.

The Busbees had gone around the region acquiring pieces made before the Civil War so they could make authentic soap dishes, plates, bowls, mugs, etc. The mugs made for the Civil War were called Confederate mugs.

We had a delightful ten days and learned a lot.