Why Flyknit is really cool

Flyknit

“Flat knitting technology’s finest hour” — Billy Hunter, knittingindustry.com

This post is based on a short talk I gave at Interesting.

I want to tell you about why I think Flyknit is really cool.

Flyknit shoes

A pair of Flyknit shoes. Image: Nike.

Flyknit is a brand name that Nike gave to a range of shoes launched in 2012. The range is characterised by uppers produced in a single piece using flat knitting technology. To understand why this is so innovative it will be helpful to understand the difference between sewing and knitting first.

Flyknit upper

A single-piece knitted upper. Image: Nike.

Sewn items rely on creating three-dimensional objects from two dimensional planes. Fabrics are usually produced by weaving strands of thread together, often over and under, producing a long, flat plane that comes on a roll.

Roll of fabric

Fabric is a flat plane, and usually comes on a roll.

To create a shirt, for example, which conforms to the shape of the human body, you have to cut out a number of pieces which can be sewn together creating a three-dimensional object.

Shirt

A shirt, for example, is sewn from many flat pieces designed to create a three-dimensional object when put together.

Shirt pieces

Shirt pieces

When cutting the pieces out of the material there is usually quite a lot of waste. The process is roughly the same for leather shoes. The leather is a flat plane, from which pieces are cut and sewn into a desired shape.

Shirt pieces
Waste from sewing processes

Due to the nature of sewing a lot of waste is produced

Knitted items are made completely differently. Let’s take an example of a jumper. To create a jumper you can think of a human body as a series of differently-proportioned tubes.

The shape can be made directly, using a single piece of thread, built up in a spiral from the top or bottom. To construct the knitted fabric each row attaches to the row below and the row above it.

Knitted row
Knitted row

Each knitted row is attached to the one below and one above

When you finish building up your object you cut off the remaining thread and you already have your three-dimensional object, created with no waste.

Nike’s Flyknit uppers still have to be sewn at the back of the heel and attached to the sole, but otherwise they are created in a single piece shaped to conform to the human foot.

Waste reduction isn’t the only reason why knitting a three-dimensional object can be better than sewing it together from pieces. Wherever you have a seam, that becomes a potential weak spot, where the natural flexibility of the fabric or other material is reduced.

Sports shoes require different kinds of performance from different areas of the shoe. Some areas need to be supportive, others breathable, other extremely flexible. The traditional approach is to use materials with different properties in different parts of the shoe to provide the appropriate performance. The downside is that each part introduces more seams.

With a knitted upper you do away with that problem entirely. Knitting allows you to vary the properties of each part of the piece as you please. Using different techniques for creating stitches and different yarns you can create a single piece that has supportive areas as well as flexible or breathable sections.

Shoe anatomy

Different parts of the single-piece upper have different material characteristics without the downside of having seams

When Nike released the first Flyknit shoe the knitting industry exploded with excitement. Billy Hunter, one of the writers for knittingindustry.com, said:

Make no mistake — this is flat knitting technology’s finest hour.

3D printing generates a lot of interest and excitement from all kinds of makers, but knitting already provides many of the benefits of 3D printing, without the downsides. It lets you create three-dimensional objects with no waste and you can make one-of-a-kind computer generated objects by scripting already existing knitting machines. Unlike 3D printing, knitting is ready for mass production now, and has been for decades. It’s reliable, there are tons of people who have the expertise to work with it, and the machines are widely available.

Knitting — not cool

So why isn’t it the technology which receives interest from makers and innovators? It’s almost as if in some people’s minds knitting is associated with women, and therefore not worth exploring.

The only companies I heard of which are really pushing the boundaries on what knitting can do are Nike, going beyond making garments, and Unmade, producing one-of-a-kind garments designed by customers in the browser. It’s about time other people realised just how much potential this technology has.

As a bonus, I want to leave you with this video of me unraveling a sock (backwards), to show you how the fabric is built up row by row.