PITTSFIELD, MASS. — They come in sunlit leaves or a dark blue surface rippling like water in shade.
They come in goldenrod-yellow butterfly wings with streaks of orange and blue or green and gold pinwheels against scarlet.
On the walls of Shire City Sanctuary, Karen Pratt of Pittsfield is showing quilts she has made for the annual Hoffman Challenge since 1997.
Hoffman California Fabrics creates screen-printed and hand-dyed cloth in a wide range of colors and patterns — Rube Hoffman, a New York textile jobber, founded the company in 1924, and three generations of his family run it today.
Every year the company chooses a pattern and sets a challenge, to create a quilt using a certain amount of it, and quilters around the world respond.
Along with the top three finalists, the judges will choose a set of the entries to travel to quilt shows across the country, Pratt said.
She has not won a top prize yet, but 12 of her quilts have joined the traveling show in the last 21 years.
She began quilting in the 1990s, she said, when her sister, Kim, took her on a quilting retreat and gave her her first Hoffman fabric.
Their mother had always sewed at home. She ran a business, the Busy Bobbin, did alterations, sewed stripes on uniforms for police officers and firefighters, made curtains and clothing for her daughters.
Karen too has made quilting into a business, Quilt Lily Designs (named for two passions, because she also loves hybridized lilies). She is a software engineer at General Dynamics, but now in her own time she invents quilt patterns.
With her friend Kate Mitchell of Kate Mitchell Quilts she has formed Berkshire Quilts, and they offer quilting retreats including one at Shaker Meadows in New Lebanon, N.Y., in September.
In her talks and workshops and quilt shows, she has met people of different ages, she said, and though many are old enough to have learned sewing at home, as she did, she has seen younger people starting to take an interest. She sees them in the crowds at quilt shows, and she has taught her friend Kathleen Harrington's daughter, Kelly.
Kelly, who came to the opening with her family, said she has made pillow cases and coasters for friends, and a small wall quilt with triangles and circles in purples and pinks and blues.
Kelly is 11, her mother said, and she has been sewing with Karen since she was 6 years old.
Over the years, Karen has experimented on her own with new designs and techniques.
Some of the quilts on display here come from her own designs, she said, and for the challenge each year she chose a new technique to learn — stitching with metallic thread, or working with curved pieces of cloth; making a square from two triangles and sewing the long sides underneath, bowing them to leave a space like a long green leaf; or cutting away a dark fabric to reveal brilliant colors beneath in a reverse appliqué like stained glass.
In "Cherry Twirl," she embossed cherries onto dark velvet by dampening an ordinary rubber stamp, pressing it into the nap on the cloth and ironing the back.
Crispina ffrench is enjoying Pratt's work, which will hang on display all this month. ffrench is co-owner of Shire City Sanctuary, Pittsfield's first makerspace, and she is a fiber artist in her own right, designing clothing and blankets and more out of upcycled sweaters and other materials.
"Karen is established in the local quilting community," she said. " There are a lot of quilting people in Pittsfield excited to see her work here."
She admired the detail in Pratt's work. The stitching gives a freedom within the set shapes of the quilt design.
A quilt begins with cut shapes of cloth pieced together, but the quilting is the pattern of stitching that holds the quilt together — the patterned top, the cotton batting in the center and the backing.
Quilt patterns often give the shapes of the pieces and leave the quilting to the imagination, Pratt said: "Quilt as desired."
Sometimes she will echo the shape of the cloth pieces or elaborate on the pattern, giving the peacock's tail in "Peace and Tranquility" a fan of feathers. Sometimes the stitches loop in intricate swirls over a plain background or deliberately challenge a shape, like the concentric rings of stitches over right angles of cloth in "Around It Goes." The half-invisible circles over squares have a dizzying quality like an optical illusion.
The stitching is subtle, Pratt said, but it can change the whole work.
"It's like drawing with thread," ffrench said. "Get close and it's a whole new realm."
IF YOU GO ...
What: Karen Pratt's quilts 1997 to 2015
Where: Shire City Sanctuary, 40 Melville St., Pittsfield, Mass.
When: Show open 5 to 10 p.m. weekdays and 10 a.m. to 5 p.m. weekends through September