Every year around May, strangers send inscrutable gifts to Marianne Lettieri. Silver platters are common, and pincushions that look like fat red tomatoes.

A farmer in Woodside once sent her an antique weed sprayer. An old woman brought her a box of cat bones.

"Objects appear on my porch like orphaned babies in baskets," she says.

Lettieri is used to people presenting her with oddities, pieces of what she calls "cultural detritus" that she uses in her mixed-media constructions. The number of gifts just goes up in the spring, after crowds drop by her Palo Alto studio during Silicon Valley Open Studios. Lettieri is one of more than 300 area artists who open their doors to the public during the annual event the first three weekends in May.

"I get all this cool stuff," she says. Excitedly, she pulls out a flat mahogany-colored box about the size of a vinyl record and flips it open. The box is full of teeth. A dentist has given her several sets of old veneers, and Lettieri regards the choppers fondly. "Aren't they just creepy enough to be fabulous?"

She laughs with evident delight, and her long earrings swing. "People don't know what to do with these things, but they don't want to throw them away."

Lettieri probably never throws anything away. But you wouldn't know it from a peek into her space at Cubberley Studios in the Cubberley Community Center. This has got to be one of the most organized studios ever. Lettieri's treasures are neatly stored on shelves and in cupboards, drawers and plastic boxes with snap-on tops, all organized by type or subject matter.

Assemblage artists are always looking for the perfect juxtapositions of objects where art is born. Fellow Cubberley Studios artist Inge Infante, who will also be in Open Studios, collects tickets, posters and other items from cities she visits. Julia Nelson-Gal, whose studio is next door to Lettieri's, gleans old photos at flea markets.

When Lettieri obtains new items — whether as gifts, at garage sales or online — she likes to group her treasures by "visual metaphors." One box is devoted to measurement: clock pieces, rulers and barometers. Others contain sand dollars and scallops, or animal bones. One is labeled simply "Pretties."

The familiar tomato pincushions fill another box. As part of her thesis at San Jose State University, where Lettieri is pursuing an MFA in sculpture, she plans to combine the pincushions into a cathedral rose window, 6 feet across, with a wooden frame. The Middle Ages meet the Victorian era, when the tomato pincushion became popular.

"For me, the pincushion is the soul of a woman," she says.

Lettieri often pays tribute to the hardworking domestic woman in her art, exploring what life was like when women couldn't have careers outside the home. She opens another box, fingering circles of handmade lace.

"This, maybe, was the only way women could express themselves. These were feats of engineering. They measured out their lives in skeins of string," she says.

It can't have been all bad, though, Lettieri muses, picking up a rolling pin. "All these pies," she says. "Think of the love that went into them."

Nearby in the studio, the assemblage "Wisp" is one of many pieces about women's lives. Lettieri has spread a white pinafore in a frame, then strung oval photos across it. Girls' faces look out from the antique graduation pictures. Mirroring age and time passing, the outlines of swallows and the skeletons of leaves dot the piece.

Another assemblage, "Church Ladies," was sold to a Palo Alto resident. It was two angel wings made from pale vintage gloves. Lettieri calls it "an homage to those women who serve others," be they housewives or house cleaners.

"I embroidered four-letter words on the gloves," she says with a giggle, "like 'cook,' 'wash,' 'bake.'"

Another theme is a gentle nudge to turn away from today's fast-paced world to appreciate "the enchantment of everyday life," she says in an artist's statement.

"Buck Saw Ace" nods to the male laborer, with a half-wing built of canvas gloves on a buck saw, their fingertips covered with red North Carolina dirt. In "They Dream and Stare Upon the Roving Sky," the artist built a miniature wooden village upon a doll pram. Faces in old photos peer out the windows but never see each other, like the neighbors who never meet each other today.

Lettieri has played her role in the high-tech world. She previously was a graphic artist in public relations. Even now, she is in the midst of a series of assemblages commissioned by Oracle Corp. Her materials are computer parts harvested from company dumpsters and given new life as triptychs.

In a sense, Lettieri's art is all about resurrection, and her Christian faith an integral part of her creativity. In 2005, she founded Arts of the Covenant, a group of artists, art therapists and art educators who explore "the intersection of Christian faith and the visual arts." About 175 people are members, meeting at the Menlo Park Presbyterian Church.

Besides holding lively discussions about the spiritual context of artworks, the members also hold exhibits and do community service. They have held art activities for spiritual retreats and made quilts for rape victims in an African hospital. This weekend, they plan to do free portraits at the VA Palo Alto Health Care System campus.

Several artists will also take part in Silicon Valley Open Studios, joining their comrades from the Peninsula down to Gilroy in opening up individual and group studios.

Lettieri and her Cubberley cohorts will open their doors the weekend of May 5 and 6, along with many other studios in Palo Alto, East Palo Alto, Stanford, Los Altos, Los Altos Hills, Ladera, Mountain View and Sunnyvale.

The weekend of May 12-13, the event moves to the South Bay, with locations in the San Jose environs and parts farther south. On May 19-20, Open Studios returns to the Peninsula: Menlo Park, Portola Valley, Woodside, Redwood City, San Carlos, Belmont, San Mateo and Hillsborough.

Studio visits are free, with no reservations required. Event hours are from 11 a.m. to 5 p.m. on Saturday and Sunday each weekend. For details, go to svos.org.