I'm putting these illustrations at the front so I will see them right away.
Because this is also my sewing information storage bin.
And this is the summary of our Bias time.

Click on 'em to enbiggen.

Vogue Pattern Magazine's last issue is the source for the image on the lower left, with notations

This is worth a minute of your time.

The warp is set on the loom and has to be straight and strong.
The weft is looped and threaded in different patterns inbetween the warp threads. It can be lighter, looser. Think of a jacquard weave, or a twill.
The thread/yarn/fiber is almost never the same weight and density as the warp.
If it's a crepe fabric, the weft is longer and curlier than the warp.
Your square grain won't stay square forever. 

Don't take my word for it? Marcy Tilton, from... [read more]