# How a PUMA Running Shoe Is Made

By Albert Fernandez

Topic: Engineering

[Open the interactive Jig](https://ask.jig.com/j/7qNg44o05clB)

## Guide

### 1. One shoe, many machines

A running shoe is not made by one magic machine\. It travels down a line of machines and skilled hands, each doing one job\. Follow this shoe, styled on a PUMA road racer, from flat fabric to finished shoe\.

Drag anywhere to turn the factory around\.

### 2. Cutting the upper

The upper is the soft top part of the shoe\. A die press pushes a sharp steel cutter, like a giant cookie cutter, down through knit fabric\. Every piece comes out exactly the same shape\.

One shoe can have up to about 20 parts\.

### 3. Stitching it together

Sewing machines join the pieces and add details like the heel and the logo\. Knit uppers need only a few seams\. The upper now looks like a soft hat, with a spare edge at the bottom for gripping later\.

### 4. Popping the foam

The bouncy midsole foam starts as a small, dense block of plastic\. In a pressure chamber, nitrogen gas soaks into it under heat and pressure\. When the pressure drops, the gas expands into countless tiny bubbles, a bit like popcorn\.

PUMA calls this nitrogen foam NITRO\. It can squash by up to 70% and spring back\.

### 5. Lasting: shaping on a foot

A last is a plastic model of a foot\. The upper is warmed to soften it, then the lasting machine's pincers pull it tight over the last\. As it cools, the upper keeps the shape of a foot\.

### 6. Glue, heat and press

The sole joins foam, a stiff carbon plate hidden inside, and grippy rubber pads\. Glue goes on the sole and the upper, and a heat tunnel warms the glue\. Then a press squeezes them together hard, because pressure makes the bond strong\.

### 7. Finishing touches

The last slides out, then workers trim stray glue, add the insole and thread the laces\. Every pair is checked for neat stitching and a firm bond before it is boxed\. Many machines and many hands made this one shoe\.