Bolt Threads debuts spider silk tie

Bolt Threads, a California-based start-up developing synthetic spider silk, has come out with its first product: a spider silk necktie. The company, which has raised some $90 million in ­venture capital funding, calls the tie the product of more than 200 person-years of research and design. Bolt sold 50 of the ties by lottery last week for $314 apiece in observance of Pi Day.