Soooo many times I get asked "What is Fleece" ..."What is it used for....do I need interfacing?" Etc etc. For some reason just the mere mention of interfacing and Fleece (also known as pellon and wadding) can make the strongest person go weak at the knees!
Interfacing is available as both sew-in and fusible and available in different weights (thicknesses) and gives support & structure to your bags and wether you use it or not depends on the weight of your fabric and design of your bag. It is almost always better to use it on major structural pieces such as flaps etc where you will find your closures such as magnetic snaps etc. In a nutshell, if your pattern instructions call for it. You should use it!
On pieces such as the bags body, the use of interfacing is optional and will depend on the look you are trying to achieve as well as your choice of fabric. Most light to medium weight fabric will benefit from it and it will give the fabric more OOMP....basically making it a sturdier and stable version of its former self!
When using heavier weight fabrics you may find it is not needed and it is important to remember that it will add bulk to your seams so if using heavier weight fabrics such as denim, bear this in mind along with your sewing machine's capabilities. Heavy fabrics and interfacing can really add a lot of bulk to major points where several seams converge etc making it difficult to sew unless you have an industrial sewing machine or other high end commercial machine....and lots of broken needles can lay testimonial to that! LOL! Speaking of needles....always use a good quality needle suitable for your fabric choice and remember to change it often! Where I have lots of layers or thicknesses, I like to use a denim needle and I almost always use a new one for each new project!
You can use interfacing on your bags lining as well for extra durability, although it may not be essential depending on your particular bag and its intended use. If you do choose to interface your lining, take care to choose a fabric/interfacing combination that is suitable for your particular bags style. Having a structured lining supporting a soft exterior doesn't often produce a good look!
Yes....there are lots of different types of interfacing and fleece to choose from and brands and availability vary from country to country and making your choice can be confusing! Generally speaking, interfacings come as woven and non woven. Non woven is cheaper and gives a different, more papery feel than the woven interfacing which is the more durable and popular choice for bags.
When choosing your interfacing you need to bear in mind the type of fabric you have chosen and the look you wish to achieve....will your combination produce enough structure or do you wish to retain more drape? Will you also be adding fleece?
Medium weight fusible cotton interfacing will suit the broadest range of fabrics and is suitable for most bags. The heavier the interfacing, the more heat and pressure you will need to fuse it to your fabric so bear this in mind if using a more delicate fabric and here you might find that you need to use a Rajah cloth (A chemically treated pressing cloth) to help protect your fabric while you apply the interfacing.
Peltex (by Pellon) is a very stiff, ultra firm stabiliser used to give your bag firm support and structure. It comes in both single sided iron on or double sided iron on. Heavy Weight Fast2Fuse, if you can get it, can be used as a substitute when your pattern calls for Peltex and, IMHO, gives a nicer result when using in curved situations. You might also like to try a layer of light weight wadding between your fabric and peltex, which gives a nice effect!
Fleece (also known as wadding or pellon) is also available as both iron-on and sew-in and in different weights. It also gives extra structure and padding to your bags. I myself prefer to use the iron on (fusible) fleece as it is lightweight and makes it very easy to sew your pieces together. I nearly always cut the fusible fleece minus seam allowance, so as to help reduce the bulk in the seams. Mostly I like to fuse my interfacing to my bags exterior and then fuse the fleece to the interfacing. This helps reduce any occurrence of those annoying wrinkles and bubbles you sometimes get on the surface of your fabric when fusing the fleece directly onto the fabric.
PHEW! There really is a lot to think about when using interfacing and fleece but it needn't be as scary as it first appears! Familiarising yourself with the different types available helps so DO experiment with them so you can learn and get a 'feel' for which to use where, according to the look you wish to achieve! Practice makes perfect! PLUS it also helps to follow the recommendations in your pattern instructions as well and if you are unsure, ask your pattern designer. Most will be happy to help you!
Happy Bag Making,