Interfacing & Interlining De-mystified - 'that's Stabilzer to our US crafting cousins.

**UPDATE** I've written more posts  to compliment this one.  They are called: Bag Making Fabrics & Interfacings and another post: How to Reinforce, or Strengthen Bags.

Woo back again; I missed posting in my blog, but I have had such busy busy week!  I had loads of orders to pack from the Xmas & New Years hols, I had a whole load of new yummy stuff arrive in the office that needed putting on the site, heaps of your emails to answer (thank you so much everybody for your kind wishes, and your gorgeous bag photos, I love 'em; they really brighten up my day!), and I also had to design and write the bag instructions this April 07's Sewing World Magazine.   PHEW!!

April 07 - Sassy Stripy Wristlet.

 

'Hello I am called 'Sassy Stripey Wristlet' and I am Sewing World's Miss April 07!'

I now have a growing list of things that I want to post about on this blog.  I think this time I'll cover Interfacing/Interlining as I had a fair amount of emails asking me about it.  To see a general definition of what interfacing is in Wiki click here. 

A not very exciting pic of some 'not very exciting sew-in interfacing',  but I'm sorry folks this stuff is ESSENTIAL in bag making!

 

What is it for? 
For bag making we need our interfacing to do some or all of these things to our fabrics: strengthen, reinforce, firm up, support, make 'boxy', make bags feel as though they are more  'substantial/better quality, sometimes to add puffiness, and most IMPORTANTLY TO PROLONG THE LIFE OF OUR BELOVED HANDIWORK.

What happens if I don't use it for my bags?
Unless you are using heavy home furnishing fabrics (which can still sometimes benefit from a helping hand from interfacing) your bags will be floppy; the material could be too thin and therefore weak; the bag may not able to take the weight of bag handles or trims; your bags will not be able to stand up on their own (which sucks if that's what you wanted your bag to do); your bags will feel thin, mean, and stingy - we all like our sandwiches to have generous fillings, and we all like the feel of soft puffy collars on our coats; in bag making it's the same, bags which feel substantial, feel nice, and feel like they are better quality.

2 types of Interfacing. 
As it says in the Wiki general definition; interfacing is available in iron-on or sew-in. Iron-on interfacing has a layer of glue on one side that is activated by the heat of (you guessed it,) your iron when you press it directly to the wrong side of your fabric.  Sew-in is where you cut the sew-in interfacing to the same shape of your fabric pattern piece (save time by laying the sew-in underneath the fabric and your pattern and cut everything all in one go).  You then treat your fabric and sew-in as one layer, hence this interfacing is sewn-into the seams - geddit?  The decision as to whether to use iron-on and/or sew-in best decided by trial and error. I know it's a pain, but it really is best to test! 

What do I often use? 
My fabric of choice is usually Quilt Weight Cotton Prints fabrics because I just looove funky prints.  However, this cotton is way too thin to use as is in bag making so I usually use some woven fusible or medium iron-on the fabric, and I will also use some fleece too to make my bags 'feel' nice (or in other words, feel slightly padded).  If I want my bag to stand up on it's own I will also use craft/weight as well.  So you see, you can also use various interfacings in combination with each other to achieve the look and feel that you want.  IF IN DOUBT EXPERIMENT!  If you find that you brought the wrong interfacing for a particular project don't worry because this stuff is sooooo useful you'll definitely end up using it for something else.

Various Interfacing Weights. 
Interfacing is available in  different weights from light weights to medium weights - to craft (pelmet) weight.  When using a iron-on you need to choose an interfacing that is slightly lighter in weight than your bag fabric this is because you don't want any creases (made due to normal bag use) to show up in your or bag.  For instance; if you used heavy weight fusible interfacing  on fine silk (that would be bad!) the silk would become paper-like, would wrinkle-up like paper, and the creases would show up in the silk (neaahh - and yes, I have done it before!).  When using sew-in the weight doesn't matter as much because creases made in the sew-in will not show up in your bag.  As a general guide for bag making you would use:

• Light weight interfacing on: fine silks, fine satins, organza, fine shirting, crepe, light weight cotton, light weight synthetics.
• Woven Fusible interfacing on: most any fabric you like.  It's woven so it will move and drape with the lightest to the heaviest fabrics.  It provides a layer of strength and support to your fabrics yet it is lightweight and unobtrusive. It's usually muslin cotton-like in it's appearance. The adhesive side is slightly bobbly.
• Medium weight fusible interfacing on: quilt weight cotton, heavy silks, heavy satins, medium weight wool, fine linen, medium weight synthetics. It looks medium-fine, one side is slightly shiny from the adhesive.
• Volume/Compressed Fleece on: any bag or purse which requires more support and a thicker spongy padded feel (such as Amy Butler's Weekender Bag or Sophia Carry - all bag).   I always use compressed fleece in purse frame purse making because this fleece adds soft structure and a good level of 'puffiness' to the purse.  This feels soft and spongey much like wool felt.
• Fusible Fleece on: any fabric that you want to add support and a light padding to.  Great for silk and satins where you want to strengthen the fabric without making it at all crisp by using normal fusible interfacing.  Very convenient to use as you can fuse it your fabrics.  Great for all other fabrics where you want the fabric to be strengthened/reinforced but you want the fabric to retain it's drape (or fluidity). This feel a little lighter than the compressed fleece. The adhesive side is full of tiny white dots of adhesive.
• *Heavy weight/firm interfacing on:  (on boxier bags or bags that need to take the weight), heavy linen, heavy wools, denim, heavy linens and upholstery/home dec weight fabric. bags that you want to have a more firmer/rigid structured, boxier shape. This interfacing helps bags to stand up on their own.  Also fab for clutch bags. This stuff feels firm (nearly card like), but it will still flex. The adhesive side feels bobbly.
• *Pellon Ultra Firm (or similar) on: bags that you want to have a more firmer/rigid structured, boxier shape. This interfacing helps bags to stand up on their own.  Also great for clutch bags.  This stuff is similar to Craft/Pelmet interfacing except that it has softer (slightly spongy) to the touch - I love the stuff.
• * Decovil on: most any med to heavy weight fabric.  Will give you fabric a leather-like handle and strength. Brilliant for larger holdall style bags, electronic gadget cases, journal covers etc.  Looks and feels like thin sheet rubber. The adhesive side is slightly shiny.
• * Woven fusible Canvas on: most any med to heavy weight fabric. Will make your quilt weight feel just like home dec weight and your home dec weight feel, well, ready for anything!
• *Fusible Foam on (fusible here and sew-in here): on any bag where you want to proct the contents, have the bag standup by itself, where you want the bag to have an upright yet yeilding structure.

* Try this nifty trick: to reduce horrible bulk at the seams trim off the sewing allowance (and a tiny bit more) from your very heavy interlining pieces before sewing.  So if for instance you are sewing with a 1cm seam allowance trim a 1.3cm margin off your heavy weight interlining pattern pieces before you use them; you'll be so glad you did! 

Still Confused?  It does get easier really, just remember to experiment first, and as a general rule,  it is usually best to use some sort of interfacing in almost all hand sewn bags.  Even if your fabric is thick it will still benefit from a bit of padding.
 

**UPDATE** I've written more posts  to compliment this one.  They are called: Bag Making Fabrics & Interfacings and another post: How to Reinforce, or Strengthen Bags.