One of the most common questions we get asked at Fabricana is what is the difference between sew-in and iron-on interfacing?
Iron-on interfacing has an iron activated adhesive on one side. Sew-in interfacing has no adhesive and needs to be basted on by hand or machine. Working with iron-on interfacing is faster than using sew-in as you do not need to baste the interfacing on but not all fabrics do well under the heat of an iron. Sew-in interfacing is often used for tailored projects such as shirts and jackets as it is mouldable and more durable as it won’t bubble compared to iron-on interfacings. If you do decide to use iron-on interfacing test it out on a scrap of fabric first to make sure it will adhere properly and produce the results you are looking for.
Besides iron-on and sew-in, there are a variety of different types of interfacing depending on your project.
Woven Interfacings - These interfacings have a woven fabric base and tend to be stronger and also hold better when working with iron-on products.
Non-Woven Interfacings - The base of non-woven interfacings is a bonded web. These interfacings are less durable than woven interfacing. In the case of iron-on products a non-woven does not adhere as well to the fabric as a woven does.
Knitted Interfacings - Knitted interfacings have a bit of give or stretch to them. They are great for lightweight fabrics or fabrics with a bit of stretch.
Hair Canvas - Hair canvas is used where a lot of structure is required such as a tailored jacket or coat. It allows the ability to add a lot of body and structure without being super stiff. It is suggested that hair canvas be dry-cleaned only.
Interfacing Alternatives - Some people choose to sew in a fabric instead of using an interfacing. Some of the fabrics used for this purpose include silk organza or cotton muslin.
Craft Stabilizers - There are sew-in and iron on stabilizers that are available where a lot of stiffness is required (such as the bottom of a bag). These include peltex, buckram and a variety of iron-on and sew-in options.
Tips for Working with Interfacing:
- Trim the corners off your interfacing to reduce bulk
- If working with sew-in interfacing, after your pieces are basted on, trim the excess interfacing within the seam allowance to help reduce bulk
- If working with iron on interfacing on heavy fabrics, you can trim the seam allowances off your interfacing before fusing to help reduce bulk.
- If only part of a garment piece is to be interfaced, make sure to test on a scrap of fabric to see if a line will be visible from the outside. If a line is visible try to adhere the interfacing to a facing rather than the garment itself, switch to a lighter weight interfacing, or consider applying the interfacing to the whole piece.