SearchResearch Challenge (10/23/24): How is it made?

 It's that time of year... 

Image by Gemini. [young woman wrapped in flannel blanket at window, pre-Raphaelite]
... "thou mayst in me behold / when yellow leaves, or none, or few, do hang..."  

Or, less poetically, the time of year when the flannel comes out.  

As I put on my beloved flannel overshirt on this chilly morning, I got to thinking about the fabric.  While I have a pretty good idea about how most fabric is made, I really don't know the mechanism of flannel.  It's warm and comfy, but how do they DO that?  How do they make it so soft and warm?  

More generally, how things are made is always a great SRS topic.  As a flute player, I've wondered how flutes got built.  There are several great YouTube videos showing the entire construction process.  (Here's an older video showing all of the steps.)  Fascinating--and now I know.  

But back to flannel... how?  

1. Can you find out how flannel cloth (e.g., that used for comfy sheets or shirts) is actually made?  How is that distinctive nap made?  

To continue the theme of how-things-are-made, the other day I happened to see a snake zipping down a forest trail in front of me.  A bit later, I saw a reference to someone as a "snake oil salesman."  I understand what that means, but every snake I've ever seen has not a gram of fat on it.  So... how? 

2. Is snake-oil a real thing, or is the falsity of "snake oil" that it doesn't really exist?  How much fat is on a snake that could then be rendered into oil?

When you search these things out, be sure to track HOW you found your answers and let us all learn how you did it.  

Still wondering about flannel creation... 

Keep searching.