March 3, 2026
Sew much math, sew much drama
How to sew a Hyperbolic Blanket (2021)
Math blanket tutorial has crafters swooning—and the site wheezing
TLDR: A mathematician’s tutorial shows how to sew a wavy “hyperbolic” blanket from fleece pentagons, turning complex geometry into cozy craft. Commenters rave about the clear seam tips while roasting the site’s glacial image loading—and laughing over a “hypergolic” misread—splitting focus between brilliant instructions and a struggling server.
A mathematician-sculptor drops a cozy bombshell: a step‑by‑step guide to sew a wavy, mind‑bending “hyperbolic” blanket using fleece pentagons, and the crowd instantly splits into two camps—those admiring the craft, and those begging the website to, well, load. The tutorial borrows a design from Helaman Ferguson’s poncho, showing how pentagons in two colors reveal straight seams (aka “geodesics,” think straight paths on a curved surface) while spreading the ruffle‑y curvature evenly. It’s math class, but make it snug.
While the article patiently walks newbies through printing a two‑page template, tracing onto cardboard, chalking fleece, and sewing 51 pieces together, top comments are pure chaos. One viewer frets the page is “being hugged to death,” joking we might need to sponsor the owner a new router—because the only thing more dramatic than a hyperbolic blanket is a hyperventilating server. Another reader admits they misread “hyperbolic” as “hypergolic” (rocket fuel!) and braced for explosions before realizing this tutorial actually teaches the mysterious art of curved seams—and they’re here for it.
So yes, it’s a feel‑good mashup: math meets maker culture, with equal parts admiration and buffering. The vibes? Craft nerds thrilled, infrastructure skeptics pleading for a site upgrade, and everyone else giggling at the fuel‑misread meme while plotting a living‑room geometry flex. Cozy, chaotic, and highly clickable.
Key Points
- •The design for the hyperbolic blanket originates from mathematician-sculptor Helaman Ferguson, adapted from his poncho.
- •The guide details creating a durable cardboard pentagon template by printing two paper halves, taping, tracing, and cutting inner/outer pentagon shapes.
- •Construction uses polar fleece in two colors, with tailor’s chalk marking both inner and outer template edges for accurate cutting.
- •Cutting workflow: rough perimeter cut to manage bulk, followed by a precise fine cut; produce 25 pentagons of one color and 26 of the other.
- •Sewing begins by placing two pentagons back-to-back with chalk marks outward and stitching with a sewing machine; further steps continue assembly (not fully included in the excerpt).