Interfacing

The ingredient behind professional-looking bags 

While you can't see the interfacing on the outside of a bag, you can certainly appreciate the difference that interfacing makes to the finished outcome of a bag.  Simply put—good interfacing is the secret ingredient behind the successful finish in a bag.

I use many different types of interlinings and interfacing in my bags from different brands. The specific type and brand I use depends on what's right for the particular project at hand and the fabric I'm using. While Pellon is the most well know, there are many other brands and suppliers.  

The most common products used for bags include:

• Fusible Woven Interfacing (such as Pellon SF101)
• Decovil Light (e.g. Pellon Decovil Light 525)
• Decovil Heavy (e.g. Pellon Decovil Heavy 526)

Beginning bag makers that usually come from Quilting and tend to use foam interfacing (such as By Annoe's Soft'n Stable or Pellon). While this is a option for cotton bags and especially open-top totes, industrial bag makers don't tend to use these as much because the foam takes up volume without giving the bag structure. For small bags and pouches some makers use Pellon Fusible Flex Foam and there are other brands. But many experienced makers avoid using a "fusible" foam because it tends to dimple the the bag when it is turned right side out. usingLeather bag makers sometimes use what's called "closed-cell-foam"because its thinner and a bit stiffer more appropriate for use with leather.

Its good to test different products to see what you like. Feel the body, viscosity and amount of glue.  Look carefully and inspect the glue backing. Some glue flakes off, some have too much glue as compared to fiber which tend to make the fused fabric wrinkle and also can burn with too much heat applied. Some are softer/more flexible, some are stiffer, and some are more tightly woven. (Hold them up to the light to see the woven density.) The ones designed specifically for garment sewing tend to be bit stiffer.