So, I am making a coat. It is actually a "yard duty" coat. A yard duty coat is one that you wear for that infintely long twenty minute sojurn into the Canadian arctic conditions in winter to supervise students at recess.
A yard duty coat must be warm. It is really its only requirement. I bought some lovely black, boiled wool last winter and when assessing it for my coat project, decided I needed something more. I was going to interline it with a heavy material, but the clerk at the fabric store suggested I use "jacket insulation:. Let me tell you all about jacket insulation: it is spongy, about a centimeter thick and it promises to warm even to minus 25 degrees Celisius. The clerk told me that this is the material that Thinsulate uses.
Jacket Insulation basically comes in two brands:
Primaloft contains a patented microfiber that retains heat. It’s, breathable, water repellent, and as warm as down. Primaloft One is made entirely of specially treated microfibers that have the softest hand; it’s available in two weights.
Thinsulate is a blend of 55-percent olefin fiber and 45-percent polyester that comes in a variety of weights and thicknesses. These thermal products have a nonwoven layer on one or both sides to hold the fibers in place. They are washable and dry cleanable. It cost me about $11/metre.
Remember: you can interline with anything. So don't feel limited to the two above-named sources. Especially if you live in a warmer climate, and lets face it, pretty much anywhere is warmer than Ontario.
How much do you need?
Don't make my mistake: I bought enough for the entire jacket. Instead buy only enough for the body of the jacket. Typically you don't interline sleeves with jacket insulation. (And since I am so stubborn that I have to try anyway, I can assure you that even that small addition to the sleeves restricts movement and bulks one up.)
Things to keep in mind when sewing insulation into a garment:
- You're fighting bulk - look for the thinnest fabric that will do the job
- Only insulate the body of the garment, not the sleeves to reduce bulk
- Pre-treat - the main fabric, lining and insulation should be compatible in terms of garment care
- Use all purpose polyester thread -unless your main fabric is wool or silk
- Sew insulation to the lining not the main fabric
- It does not take the place of interfacing
- It can provide eveness of colour when the main fabric is not opaque
- Insulation can also reinforce open weaves, prevent transparency and add support
- Trim the interlining seam allowance to reduce bulk
- If you use flannel cotten or micro-fleece as a lining, this will add warmth and you may not need to insulate your garment.