• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia
Techbolt threads

Bolt Threads is recreating fabric from spider silk

By
Leena Rao
Leena Rao
Down Arrow Button Icon
By
Leena Rao
Leena Rao
Down Arrow Button Icon
June 4, 2015, 7:30 AM ET

While in UC San Francisco’s Ph.D biochemistry and engineering program, Dan Widmaier, David Breslauer and Ethan Mirsky became fascinated with the idea of creating man-made silk from the protein fibers in the webs spiders make, called spider silk. In fact, spider silk is known to be five times stronger than steel, and tougher than man made fabric Kevlar.

The PhD students set out in 2009 to create a technology that makes these proteins without using spiders. After years in stealth research and production, Bolt Threads is finally debuting its proprietary engineered silk, along with announcing a new $32.3 million round in Series B funding.

Foundation Capital and Formation 8 co-led the round, with participation from Founders Fund. The company has raised a total of $40 million.

Bolt Threads uses proprietary technologies to create engineered silk fibers based on proteins found in spider silk that can be produced at commercial scale.

At a scientific level, Bolt actually examines the DNA of spiders and then replicates those genetic sequences in other ingredients to create a similar silk fiber.

Bolt’s silk is made primarily of sugar, water, salts and yeast, which combined makes a liquid silk protein. Through a process called wet spinning, this liquid is spun into fiber, similar to the way fibers like acrylic and rayon are made.
If you look under a microscope, says the company, Bolt’s engineered silk fibers have the exact same chemistry as naturally occurring animal silks from spiders or silk worms.

Widmaier explains that the silk fabric created by Bolt has similar qualities to conventional silk in that it will provide warmth, and a softer feel, but will be easier to wash and wear. For example, you won’t have to dry clean Bolt’s silk because it will have the durability to be washed in a machine. The company is working with textile manufacturers in North Carolina to commercially scale production of the fabric.

Bolt isn’t the only company to try to create spider silk at mass. Japanese startup Spiber is marketing a similar fiber. German company Amsilk is also developing commercial grad spider silk.

The company will be using the new funding to expand production and comercialization of its silk fabric.

Subscribe to Data Sheet, Fortune’s daily newsletter on the business of technology.

About the Author
By Leena Rao
See full bioRight Arrow Button Icon

Latest in Tech

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025

Most Popular

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Fortune Secondary Logo
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • Future 50
  • World’s Most Admired Companies
  • See All Rankings
Sections
  • Finance
  • Fortune Crypto
  • Features
  • Leadership
  • Health
  • Commentary
  • Success
  • Retail
  • Mpw
  • Tech
  • Lifestyle
  • CEO Initiative
  • Asia
  • Politics
  • Conferences
  • Europe
  • Newsletters
  • Personal Finance
  • Environment
  • Magazine
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
  • Group Subscriptions
About Us
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map
  • Facebook icon
  • Twitter icon
  • LinkedIn icon
  • Instagram icon
  • Pinterest icon

Latest in Tech

lancaster
AIschools
Two private school boys get probation for using AI to create 350 fake nudes of their classmates
By Mark Scolforo and The Associated PressMarch 25, 2026
4 hours ago
melania
PoliticsWhite House
Enter Melania Trump, escorted by humanoid robot: ‘I’m Figure 03, a humanoid built for the United States of America’
By Darlene Superville and The Associated PressMarch 25, 2026
4 hours ago
bernie
AICongress
Bernie Sanders and AOC launch bill to ban new data-center construction
By Matthew Daly and The Associated PressMarch 25, 2026
4 hours ago
Big TechSocial Media
A court just ruled that tech addiction is real—and dangerous. It could be Meta and YouTube’s Big Tobacco moment
By Kristin StollerMarch 25, 2026
5 hours ago
Warner gestures
AIAmerican Politics
New college grad unemployment will spike to 35% in 2 years, senator warns, forcing ‘Dario, Sam’ to quit AI fear-mongering
By Jacqueline MunisMarch 25, 2026
6 hours ago
Big TechMeta
Meta and YouTube found liable in landmark child social media harm case, ordered to pay $3 million—with punitive damages still to come
By Kaitlyn Huamani, Barbara Ortutay and The Associated PressMarch 25, 2026
6 hours ago

Most Popular

Magazine
The youngest-ever female CEO of a Fortune 500 company is fighting Trump's cuts to keep Medicaid strong
By Fortune EditorsMarch 24, 2026
2 days ago
Commentary
The Treasury just declared the U.S. insolvent. The media missed it
By Fortune EditorsMarch 23, 2026
2 days ago
Success
Palantir’s billionaire CEO says only two kinds of people will succeed in the AI era: trade workers — ‘or you’re neurodivergent’
By Fortune EditorsMarch 24, 2026
1 day ago
Success
The job market is so bad that ‘reverse recruiters’ are charging $1,500 a month just to help people look for jobs
By Fortune EditorsMarch 25, 2026
17 hours ago
Energy
Nobel laureate Paul Krugman calls it 'treason': $580 million in suspicious oil futures traded minutes before Trump's Iran reversal
By Fortune EditorsMarch 24, 2026
1 day ago
Success
JPMorgan has started monitoring the keystrokes, video calls, and meetings of its junior investment bankers—and they say it's for employee well-being
By Fortune EditorsMarch 24, 2026
1 day ago

© 2026 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.