Questions for the fabric experts here.

[Kyrah Abattoir]

Don't know if this fits the modeling section, but hey it's about modeling and texturing...

So I've slowly been considering work on a new project, and started gathering reference material and fabrics to study. There is something that I can't quite understand:

(this example is some 65/35 poly/cotton blend I think)

This is something you see on a lot of fabrics, mostly jeans and other cotton-type fabrics that have a certain stiffness.
I'd like to reproduce this but to do so I need to understand why it is happening :

• Why does the fabric ends up with these little creases on the hem?
• Is it caused by the stitching being tighter than the fabric it is holding?
• Is it something else?

If you know, please enlighten me.

[Rolig Loon]

As you push two layers of fabric through a sewing machine to stitch them together, you are aided by the foot on top, which applies gentle pressure to hold the fabric down and by feed dogs that shove the fabric along from the underside.  (See discussion here...  https://www.sewingpartsonline.com/blog/beginners-guide-sewing-sewing-machine-parts-reference-guide/) . Without those parts, you'd have a hard time keeping the layers moving together and keeping your fingers from being pierced and bloody.  The action is not perfect, though, because even then the layers can slide, so that one layer gets slightly ahead of the other.  They pucker a little, no matter how hard you try.  In the days when most of us were taught to sew at home, we learned how to try to control the fabric so things like that didn't get out of control, but they are really hard to avoid completely.

Edited June 6, 2019 by Rolig Loon

[Kyrah Abattoir]

Oh i see so this is because the two layers aren't completely synced?

[Rolig Loon]

2 minutes ago, Kyrah Abattoir said:

Oh i see so this is because the two layers aren't completely synced?

In a word, yes.  It gets worst when you are sewing two different kinds of fabric, so that one is slipperier than the other or stretches a little more.  It's tough to get non-rigid layers to move together.

[Love Zhaoying]

Just now, Rolig Loon said:

In a word, yes.  It gets worst when you are sewing two different kinds of fabric, so that one is slipperier than the other or stretches a little more.  It's tough to get non-rigid layers to move together.

That is when you use “interface” material. I know because I have an embroidery machine.

[Rolig Loon]

3 minutes ago, Love Zhaoying said:

That is when you use “interface” material. I know because I have an embroidery machine.

Yes, a layer of a third interfacing fabric between two layers that don't play together nicely is one way to keep them moving along well.  It also makes the seam a little less stretchy in the end so it doesn't fail later.

[Love Zhaoying]

9 minutes ago, Rolig Loon said:

Yes, a layer of a third interfacing fabric between two layers that don't play together nicely is one way to keep them moving along well.  It also makes the seam a little less stretchy in the end so it doesn't fail later.

A good “locking stitch” helps, too..