Wilhelm Seam offers handmade leather items in Somerville

By day, Jason Jammallo is a mechanical engineer specializing in manufacturing innovation. On his own time, with support from his finance, Brittany Hamtil, he’s the man behind Wilhelm Seam handmade leather goods, such as wallets, organizers, key chains, and other accessories.

Jammallo, 30, of Somerville, said he has always enjoyed working with his hands. He started with woodworking, then moved to leather because “it lives and breathes with you. It breaks into the way a person uses it and makes the piece truly unique.”

He started making items for friends and family, then began producing small batches, working several nights a week in the kitchen of his condo. The operation has spread to a second bedroom, and he’s looking for artist workspace in Somerville.


Still, Jammallo, who has a degree in mechanical engineering from Renssselaer Polytechnic Institute and a master’s from Tufts University, said he won’t be leaving his day job.

Wilhelm Seam is “a passion project,” he said. “It’s not a money thing. It’s more important that people enjoy and are excited about what I am making.”

Q. Leather?

A. I get it from a number of sources locally and buy surplus leather online. While I am driven by the colors and what looks good to my eye, my primary concern is finding the highest quality.

Q. Process?

A. I design on CADD software and use laser cutters and printers to make the templates. Then I cut, punch, and stitch every piece by hand.

Q. Customers?

A. Generally, mid-20s to 40s. I sell at artisan shows, pop-up events, and locally. People have been reaching out to me from all over the world, asking how to get something I have made. Now, I am focusing on selling face-to-face in the Boston area. People are eager to get unique local products.


Q. Cost?

A. $39 for a simple wallet, up to $110 for a more complicated one. I have four models.

Q. Future?

A. When I get more space, I plan to make totes, handbags, duffels, and backpacks. My goal is to keep growth as organic as possible.

Q. Bottom line?

A. People want something that is unique and will last years. Depending on how a person uses it, a piece can last a very long time, which is important to me. Should anything happen, I am happy to make repairs. I hope a person loves it enough that he or she wants to repair it rather than replace it. I want to make things people care about.

Wendy Killeen can be reached at